over @ ForTheRecord (Mediaportal TV Server alternative/option) they are adding NIT scanning into their next release of 4TR
Im not sure how to answer their questions correctly, but im sure someone here does.
See below the question they posted.
To improve NIT scanning, can you post the frequencies to scan for your provider?
For example (and please do correct me if I'm mistaken):
TV Vlaanderen DVB-S
As I said, if I'm not mistaken, scanning both these frequencies will give you the NIT tables for TV Vlaanderen.
EDIT: thinking out loud I'd say we could create an online NIT file (probably using an XML format) which could be downloaded by Argus before a scan. That way you (the user) could help keep this file/database up to date for all For The Record users.