This MACE_readme20251014.txt file was generated on 20251014 by Madison Golden ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Impact on Cloud Properties of Reduced-Sulphur Shipping Fuel in the Eastern North Atlantic 2. Author Information Principal Investigator Contact Information Name: Gerald G. (Jay) Mace Institution: University of Utah Department: Department of Atmospheric Sciences Address: Stewart Building, 270 S 1400 East Room E2108 ST, Salt Lake City, Utah 84112, USA Email: jay.mace@utah.edu ORCID: 0000-0001-7338-7726 Associate or Co-investigator Contact Information Name: Sally Benson Institution: University of Utah Department: Department of Atmospheric Sciences   Address: Stewart Building, 270 S 1400 East Room E2108 ST, Salt Lake City, Utah 84112, USA   Email: sally.benson@utah.edu   ORCID: 0000-0003-1947-3118 3. Date of data collection (single date, range, approximate date) 2016-06-01 to 2023-09-3 4. Geographic location of data collection (where was data collected?): ENA ARM Site at Latitude +39.0916 N, Longitude -28.0257 W 5. Information about funding sources that supported the collection of the data: NA -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC BY 2. Links to publications that cite or use the data: https://doi.org/10.5194/egusphere-2025-2075 3. Links to other publicly accessible locations of the data: NA 4. Links/relationships to ancillary data sets: Citations of the datasets collected at the Eastern North Atlantic (ARM) user facility that was used in the study of cloud properties. Atmospheric Radiation Measurement (ARM) user facility. 2015. Cloud Condensation Nuclei Particle Counter (AOSCCN1COLAVG), 2015-01-01 to 2020-10-28, Eastern North Atlantic (ENA) Graciosa Island, Azores, Portugal (C1). Compiled by A. Koontz, C. Flynn, E. Andrews, J. Uin, O. Enekwizu, C. Hayes and C. Salwen. ARM Data Center. Data set accessed 2025-10-07 at http://dx.doi.org/10.5439/1255094.; Atmospheric Radiation Measurement (ARM) user facility. 2021. Cloud Condensation Nuclei Particle Counter (AOSCCN2COLAAVG), 2021-06-29 to 2025-10-06, Eastern North Atlantic (ENA) Graciosa Island, Azores, Portugal (C1). Compiled by A. Koontz, J. Uin, E. Andrews, O. Enekwizu, C. Hayes and C. Salwen. ARM Data Center. Data set accessed 2025-10-07 at http://dx.doi.org/10.5439/1323894.; Atmospheric Radiation Measurement (ARM) user facility. 2014. Meteorological Measurements associated with the Aerosol Observing System (AOSMET), 2014-01-10 to 2025-10-06, Eastern North Atlantic (ENA) Graciosa Island, Azores, Portugal (C1). Compiled by J. Kyrouac, S. Springston and M. Tuftedal. ARM Data Center. Data set accessed 2025-10-07 at http://dx.doi.org/10.5439/1984920.; Atmospheric Radiation Measurement (ARM) user facility. 2014. Microwave Radiometer, 3 Channel (MWR3C), 2014-02-25 to 2025-10-06, Eastern North Atlantic (ENA) Graciosa Island, Azores, Portugal (C1). Compiled by M. Cadeddu, G. Gibler, A. Koontz and M. Tuftedal. ARM Data Center. Data set accessed 2025-10-07 at http://dx.doi.org/10.5439/1025248. Citations for the NASA satellite data that was used in the study of cloud properties: Platnick, S., Ackerman, S., King, M., et al., 2015. MODIS Atmosphere L2 Cloud Product (06_L2). NASA MODIS Adaptive Processing System, Goddard Space Flight Center, USA: http://dx.doi.org/10.5067/MODIS/MOD06_L2.061, http://dx.doi.org/10.5067/MODIS/MYD06_L2.061 NASA/LARC/SD/ASDC. (2014). CERES Single Scanner Footprint (SSF) TOA/Surface Fluxes, Clouds and Aerosols Aqua-FM3 Edition4A [Data set]. NASA Langley Atmospheric Science Data Center DAAC. Retrieved from https://doi.org/10.5067/AQUA/CERES/SSF-FM3_L2.004A NASA/LARC/SD/ASDC. (2014). CERES Single Scanner Footprint (SSF) TOA/Surface Fluxes, Clouds and Aerosols Terra-FM2 Edition4A [Data set]. NASA Langley Atmospheric Science Data Center DAAC. Retrieved from https://doi.org/10.5067/TERRA/CERES/SSF-FM2_L2.004A 5. Was data derived from another source? Yes: We compare observations collected at the Atmospheric Radiation Measurement program’s (ARM) Eastern North Atlantic site (ARM-ENA, 39.1 N, 28.0 W) with MODIS and CERES NASA satellite data collected in the vicinity of ENA. 6. Recommended citation for the data: Mace, G.G., Benson, S. (2025) Impact on Cloud Properties of Reduced-Sulphur Shipping Fuel in the Eastern North Atlantic. The Hive: University of Utah Research Data Repository. https://doi.org/10.7278/S5d-ppzy-3nkj --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: calculate_lidar_atten_backscatter_profile_liquid_cloud.pro Short description: Called by nd_oe_forward_model.pro  Calculates the molecular lidar backscatter and extinction profile. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. B. Filename: ccn_ss_regression.pro Short description: Called by ena_nd_retrieval_clean.pro  Regresses a time series of ccn measurements taken at a sequence of supersaturations to an input supersaturation. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. C. Filename: compare_ena_ccn_mwr_cloud.pro Short description: This code reads in the processed data files including ccn data files and  cloud property retrievals and creates the files used to make Figure 2. This code writes the files called ena_cld_pre.cdf, ena_cld_post.cdf, ena_lwp_pre.cdf, ena_lwp_post.cdf, ena_ccn_pre.cdf, ena_ccn_post.cdf. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. D. Filename: dlnbeta_dz_fit_submaxz_sb.pro Short description: Called by ena_nd_retrieval_clean.pro  Uses linear fit of lidar backscatter to estimate cloud base. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. E. Filename: ena_ks_test_modis.pro Short description: This code reads in the data file ena.MOYD.range_ring_vectors.201605-202309.029_048lat.-39_-16lon.cdf.  The code performs Kolmogorov-Smirnov statistical tests and outputs the data files needed for Figure 3. The data file is located in the folder data_files_for_analysis. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. F. Filename: ena_nd_retrieval_clean.pro Short description: The main code to perform the cloud number density and precipitation rate retrievals for clouds above the Eastern North Atlantic (ARM) user facility. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. G. Filename: eval_large_scale_cloud_controlling_factors.pro Short description: This code reads in the files called shiptrack_full_data_pre_daily.nc4 and shiptrack_full_data_post_daily.nc4 and creates the files used to make Figure 1.  The data files are located in the folder data_files_for_analysis. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. H. Filename: extinction_via_slope.pro Short description: Called by calculate_lidar_atten_backscatter_profile_liquid_cloud.pro  Calculates extinction with a fixed radar range gate. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. I. Filename: extinction_via_slope_sb.pro Short description: Called by ena_nd_retrieval_clean.pro  Calculates extinction which is entirely from multiple scattering and independent of cloud layer base or top. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. J. Filename: get_cold_prior_reduced.pro Short description: Called by retrieve_nd_fad_re_from_zmax_ext_eta_ztop_nofad_test3.pro. Gets the data from the Socrates experiment to use as a first guess for the  optimal estimation retrieval. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. K. Filename: kstwo_nin.pro Short description: Called by ena_ks_test.pro, ena_ks_test_modis.pro, eval_large_scale_cloud_controlling_factors.pro and read_plot_ena_vectors.pro Performs the two-sided Kolmogorov-Smirnov statistic. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. L. Filename: lidar_gas_rayleigh_backscatter_extinction_functionuse.pro Short description: Called by calculate_lidar_atten_backscatter_profile_liquid_cloud.pro  Calculates the Rayleigh backscatter coefficient for clear air. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. M. Filename: lin_histo_2_logplot.pro Short description: Called by compare_ena_ccn_mwr_cloud.pro, ena_ks_test.pro, read_plot_ena_lwp.pro, and read_plot_ena_vectors.pro. Plots a linear variable on a logarithmic scale. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. N. Filename: moist_adiabatic_lapse_rate.pro Short description: Called by calculate_lidar_atten_backscatter_profile_liquid_cloud.pro  Calculates the moist adiabatic lapse rate with the goff-gratch equation. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. O. Filename: moist_adiabatic_lapse_rate_jay.pro Short description: Called by ena_nd_retrieval_clean.pro. Calculates the moist adiabatic lapse rate. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. P. Filename: nd_dlnbeta_calc.pro Short description: Called by ena_nd_retrieval_clean.pro. Initial cloud droplet number density retrieval calculation. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. Q. Filename: nd_oe_forward_model.pro Short description: Called by retrieve_nd_fad_re_from_zmax_ext_eta_ztop_nofad_test3.pro. Calculates the observables for the cloud droplet number optimal estimation retrieval algorithm. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. R. Filename: nd_zm_fad_eta.pro Short description: Called by calculate_lidar_atten_backscatter_profile_liquid_cloud.pro. Calculates the cloud number density for a given cloud adiabaticity. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. S. Filename: read_plot_ena_lwp.pro Short description: Reads MWR and Surface Met data from ENA and writes the file used to create Figure 2g.   The data files, enamwr3cC1.b1 and enaaosmetC1.a1, can be downloaded from arm.gov. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. T. Filename: read_plot_ena_vectors.pro Short description: This code reads in the files created by compare_ena_ccn_mwr_cloud.pro  and writes the histogram files used to create Figure 2.  Data files are located in the folder data_files_for_analysis. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. U. Filename: retrieve_nd_fad_re_from_zmax_ext_eta_ztop_nofad_test3.proalbedo_PRE_POST.cdf Short description: Called by ena_nd_retrieval_clean.pro. Optimal estimation algorithm to retrieve cloud droplet number density and cloud layer adiabaticity from lidar backscatter extinction. 1 of 21 files needed for the code to run the microphysical retrieval algorithm as explained in the file readme. V. Filename: albedo_PRE_POST.cdf Short description: CERES cloud albedo for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code W. Filename: ccn_PRE_POST.cdf Short description: Cloud Condensation Nuclei (CCN) measured at 0.2% supersaturation for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code X. Filename: cn_PRE_POST.cdf Short description: Condensation Nuclei for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code Y. Filename: lwp_oe_PRE_POST.cdf Short description: Cloud liquid water path (g/m2) retrieved by the optimal estimation algorithm for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code Z. Filename: nd_oe_PRE_POST.cdf Short description: Cloud droplet number concentration (#/cm3) retrieved by the optimal estimation algorithm for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code AA. Filename: pwv_PRE_POST.cdf Short description: Precipitable water vapor for the pre-2020 and post-2020 observation periods 1 of 10 file outputs from the code AB. Filename: optical_depth_PRE_POST.cdf Short description: Cloud optical depth for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code AC. Filename: rain_rate_PRE_POST.cdf Short description: Rain rate (mm/day) for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code AD. Filename: re_oe_PRE_POST.cdf Short description: Cloud top effective radius (microns) retrieved by the optimal estimation algorithm for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code AE. Filename: wind_speed_during_clds_PRE_POST.cdf Short description: Wind speed (m/s) during clouds for the pre-2020 and post-2020 observation periods. 1 of 10 file outputs from the code AG. Filename: ena.MOYD.range_ring_hist.201606-202309.029_049lat.-41_-14lon.cdf Short description: The CERES and MODIS NASA satellite retrieved cloud properties within 1000 km of the ENA site for the pre-2020 and post-2020 observation periods. 2. Relationship between files: This directory contains the code and prior data files to run the microphysical retrieval algorithm documented in the following papers: Mace, G.: Deriving cloud droplet number concentration from surface based remote sensors with an emphasis on lidar measurements, Atmos. Meas. Tech., 17, 3679-3695, https://doi.org/10.5194/amt-17-3679, 2024. Mace, G. G., Sally Benson, Elizabeth Sterner, et al. The Association Between Cloud Droplet Number Over the Summer Southern Ocean and Air Mass History, Journal of Geophysical Research, Atmospheres, 129, e2023jd040673, https://doi.org/10.1029/2023JD040673. Mace, G. G., Benson, S., Gombert, P., and Smallwood, T.: Impact on Cloud Properties of Reduced-Sulphur Shipping Fuel in the Eastern North Atlantic, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2025-2075, 2025. The code is written in the idl language and is run in IDL 8.8.2 Apr 06 2022 (430118) (c) Copyright 1988-2022 L3Harris Geospatial Solutions, Inc. The main code to begin cloud property retrievals is called ena_nd_retrieval_clean.pro All routines necessary to run the code that are not part of the idl distribution are contained in this directory. Additional data files needed to run the code are located in folders called: Socrated nd_fad_oe_kx The paths to these data files are defined in retrieve_nd_fad_re_from_zmax_ext_eta_ztop_nofad_test3.pro All other paths are defined at the top of the ena_nd_retrieval_clean.pro Other codes to do analysis of data are: compare_ena_ccn_mwr_cloud.pro: This code reads in the processed data files including ccn data files and cloud property retrievals and creates the files used to make figure 2. The code writes the files called ena_cld_pre.cdf, ena_cld_post.cdf, ena_lwp_pre.cdf, ena_lwp_post.cdf, ena_ccn_pre.cdf, ena_ccn_post.cdf read_plot_ena_vectors.pro: This code read in the data files created by compare_ena_ccn_mwr_cloud.pro and writes the histogram files used to create Figure 2. Data files are located in the folder data_files_for_analysis. eval_large_scale_cloud_controlling_factos.pro: This code reads in the files called shiptrack_full_data_pre_daily.nc4, shiptrack_full_data_post_daily.nc4 and creates the files used to make Figure 1. The data files are located in the folder data_files_for_analysis. ena_ks_test_modis.pro: This code reads in the data files ena.MOYD.range_ring_vectors.201605-202309.029_048lat.-39_-16lon.cdf and does KS tests and outputs the data files needed for Figure 3. The data file is located in the folder data_files_for_analysis. read_plot_ena_lwp.pro: Reads MWR and Surface Met data from ENA and writes the file used to create figure 2g. The data files are located in enamwr3cC1.b1 and enaaosmetC1.a1 in the data folder of this distribution. ena_ks_test.pro: This code reads in data files created by previous routines and does Kolmogorov-Smirnov tests on that data. Data files are in this folder. This routine calls procedures kstwo_nin.pro and lin_histo_2_logplot.pro located in the folder data_files_for_analysis. Jay Mace October, 2025 jay.mace@utah.edu 3. Additional related data collected that was not included in the current data package: NA 4. Are there multiple versions of the dataset? yes/no No -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: We select the MODIS and CERES observations of marine boundary layer cloud properties collected within 250 km of the ARM-ENA site. These observations are compiled from cloud covered pixels deemed to contain marine boundary layer clouds.  In addition, we examine cloud properties derived from ARM data collected at the ARM-ENA site during periods of northeasterly flow that have been shown to have air with unmodified marine characteristics. For a complete description, please see: Mace, G.: Deriving cloud droplet number concentration from surface based remote sensors with an emphasis on lidar measurements, Atmos. Meas. Tech., 17, 3679-3695, https://doi.org/10.5194/amt-17-3679, 2024. 2. Methods for processing the data: A series of regulation changes from the International Maritime Organization that culminated in 2020 reduced the Sulphur content of global shipping fuel from ~3.5% to 0.5%. This change has been shown to dramatically reduce the occurrence of visible ship cloud tracks in satellite imagery.  To study the effects on clouds, we divide the data into pre-2020 (2016, 2017, 2018) and post-2020 (2021, 2022, 2023) periods. 3. Instrument- or software-specific information needed to interpret the data: The code is written in the idl language and is run in: IDL 8.8.2 Apr 06 2022 (430118) (c) Copyright 1988-2022 L3Harris Geospatial Solutions, Inc.  IDL is a widely used software in the field of atmospheric sciences, and licenses to execute the code are often held by atmospheric sciences departments and labs. . pro is the file extension for IDL code documents. The files can be opened and edited by any text editor. However, they can only be executed to produce the numerical results and images by the IDL language software and a license is needed in order to run the code and produce results. . cdf is the file extension for files in the NetCDF (Network Common Data Form) binary file format. It is referenced here: https://www.unidata.ucar.edu/software/netcdf. NetCDF files are binary so they can only be opened using software libraries specifically written to work with these binary files. These software libraries are usually included with most major programming languages and can be freely downloaded 4. Standards and calibration information, if appropriate: NA 5. Environmental/experimental conditions: We examine data collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Eastern North Atlantic (ENA) site located on the Portuguese Island of Graciosa in the Azores Archipelago. We focus on the warm season (June-September) when the Azores anticyclone migrates northward and brings a higher frequency of northeasterly flows to the Azores and a high occurrence of marine boundary layer clouds over the ARM-ENA site. 6. Describe any quality-assurance procedures performed on the data: NASA and DOE ARM had already done the quality assurance procedures 7. People involved with sample collection, processing, analysis and/or submission: NA DATA-SPECIFIC INFORMATION NOTE: Code files are not included in the below data-specific information section. Necessary information regarding their contents, purpose/function in relation to the following files, and software-specific details are included in earlier sections of this README file. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: albedo_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: ccn_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: cn_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: wp_oe_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: nd_oe_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: pwv_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: optical_depth_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: rain_rate_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: re_oe_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: wind_speed_during_clds_PRE_POST.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: ena.MOYD.range_ring_hist.201606-202309.029_049lat.-41_-14lon.cdf ----------------------------------------- 1. Number of variables: 2. Number of cases/rows: 3. Variable List A. Name: [variable name] Description: [description of the variable] Value labels if appropriate B. Name: [variable name] Description: [description of the variable] Value labels if appropriate 4. Missing data codes: Code/symbol Definition Code/symbol Definition 5. Specialized formats of other abbreviations used