Documentation about "tag rules"?

[liar666]

Hi,
I can't find any documentation about "tag rules". The only mention I found on the whole web was on this issue:
#84
I tried to use "condition"s like: feed-title contains "51" but the "Save" button remains disabled, so the syntax is not accepted.

Where can we find the correct syntax for "tag rules"?

[Frostbyte8]

The only place the author documented it was in an old update message found here: https://tughi.github.io/aggregator-android/2020/04/07/preview-027.html

As far as I can tell though, text filtering can't be made to be case insensitive.