Originally Posted by DoctorOhh
In the Calibre forum Old Threads rarely have any relevant information. Calibre updates its features and fixes program bugs about once a week. An Old thread is frequently 26 to 100+ versions behind the current version and most items simply do not apply any more.
When someone resurrects an old thread it pops up to the top of the forum and well meaning folks waste their time helping an Original poster that had his/her post answered a year ago. It can be very annoying to those that have been active in calibre's forums for 6 months to a year and a half. After that time frame you rarely get caught because answering an original poster because you are often subscribed to the threads and you pick them up with the offending necropost and not at the beginning of the thread.
Understand what you are saying, but two comments - narrowing it down to a technology thread like calibre is somewhat skewing the argument; and you always have the option to unsubscribe from/ignore an old thread.
If it's really that much of an issue, then I like BetterRed's suggestion of "a feature to create a 'Related Thread' that injected a link to the 'Old Thread' into the post would be useful." This would no doubt create a not insignificant amount of coding, though, and I doubt it would be worth the effort.