Hi,
Thanks for the idea but honestly I don't think that it would be possible.
Thread subscriptions are stored in a forum application table in the database, so when it displays a forum listing, forum application is retrieving necessarry information from this table by matching with the session user that helps indicating if the thread is "subscribed" by the visiting user or not.
When you unsubscribe, this entry in the subscription table is simply deleted. Therefore there is no indicator that shows you "unsubscribed" from that thread, but it just indicates that you are not subscribed to the thread.
To make this idea real, what necessary is making forum application to work with another custom table that would be storing "unsubscription" records that would be used for identifying "unsubscribed" threads just like subscriptions. This means:
1- Modification in forum application and database
2- More load on the database by considering the new queries during the listing, during the subscription and during the unscubscription attemps.
If it was MrExcel Board on phpbb application back on March 2002 when I first applied "red topics" logic like too many other good ideas like this one, then I would have modded the application for this good idea as well. However, we are not modding the forum application anymore simply because we want it to be stable and easily upgradable no matter who manages the technical side and current MrExcel.com forum is perhaps 20x larger than 2002. It makes more sense if we consider that it took more than a year to decide on the forum application migration including countless test migration attempts that failed most of the time that caused delays on this decision and about 6 months to make the live migration to current vBulletin application since the old heavily modded phpbb application was the biggest problem that we had about the migration as well as ~3GB huge database.
I tried to explain less technical by considering that future readers might not be involved with PHP scripting and/or databases and sessions and I hope it makes sense.
Thanks again.
Suat