You are on the Tridion StackExchange site, using this tag is redundant, so don't use it ;)
This tag should be deleted, but if we do, there will be somebody who will just create it again, seeing the amount of times it is used. So let's leave this tag here, with this info. However we should not use this tag on any of our questions because it is unnecessary clutter. It has no value, since SDL Tridion is the name of the product (currently actually called SDL Web) this site is based on.
If you see a question using this tag, please edit the question and remove this tag from the question.