In a Socure consumer data file, what do the substrings "_LFM_" and "_CHM_" signify in the field "rowIdSource"?

External question — Personal Finance Stack Exchange Author: TyrannicalDuncery Original post: https://money.stackexchange.com/questions/164965 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. The data broker Socure gave me my consumer report. It contains a number of unlabeled .json files with unlabeled records. I'm looking at one called "1.json." Each record contains a field called "rowIdSource"; the values in this field all contain either "LFM" or "CHM". The records with "LFM" have a much higher error rate. Most are mailing addresses. One of the records with "CHM" is wrong, but I've seen it before in one and only one place: my Equifax credit report. I removed it by dispute in 2024. The rest of the "CHM" records are correct and obvious (name, address, prior address, DOB, SSN, phone number). Does anyone have any idea what these substrings "LFM" and "CHM" represent? I would appreciate guesses even if you don't have a definitive answer. I asked Socure for a data dictionary a few weeks ago; they haven't responded yet but I think they might. I'll let you know if they do. However, I don't think they are likely to tell me what "LFM" and "CHM" mean because these might describe data providers with whom they have confidentiality agreements.