Global minimum ratio ranges between 0.4-1.2 depending on amount downloaded. No mention of MR or MST for individual torrents.
https://www.hddolby.com/faq.php
* brasiltracker: correct MR and MST
"After downloading at least 95% of a torrent, you must seed for at least 48 hours or until you have seed at least one full copy (1:1)."
https://brasiltracker.org/wiki.php?action=article&id=201
Global ratio ranges from 0-0.6
https://brasiltracker.org/rules.php?p=ratio
* gigatorrents: add MST
"Maximum seed commitment time is 2 days!" - assuming that's a bad Google translation and should be 'Minimum'.
https://gigatorrents.ws/wiki.php?action=article&id=25
There is a global minimum ratio of 0.5, but this doesn't seem to apply to seed obligation (HnR).
https://gigatorrents.ws/wiki.php?action=article&id=10
* greekdiamond: add MST
"Always make sure your ratio is above 1.00 [...] We need all users to keep live files that download 72 hours or give back the volume of the file"
https://greekdiamond.info/index.php?page=faq
* hdzone: add MR and MST
"Share rate < 1.2 will lead to account blocking [...] Seeds with the H&R logo must be planted for 336 hours within 60 days or the share rate reached 1"
https://hdzone.me/rules.php
* polishsource: add MST
"You are expected to seed every torrent for at least 48 hours during the course of 14 days since finishing the download. Ratio on a position is irrelevant."
https://polishsource.cz/rules.php
* Update uniongang.yml
"Users with a rating below 0.20 and more than 30 GB in the "Download" graph receive a message containing a warning and advice to raise the rating in the next two weeks to at least 0.30."
https://www.uniongang.net/faq.php
No mention (that I could see) of time or ratio minimums for individual seeds.
* gigatorrents: add MR
* hddisk: add MR
Global MR ranges from 0.4-0.8 depending on how much you have downloaded
https://hddisk.life/faq.php
* hdzone: remove MST
* uniongang: correct MR