Creating and Editing Tags
When you first create a Question, you should add some relevant tags in the Tag input area below the Question input area. The tags entered can be altered later. The tags you enter will be converted to lower-case. Separate tags with commas (not with semi-colons). Do not use # in front of the names.
You can use a tag phrase that did not previously exist, creating your own tag, but if you are discussing a common topic, it is much recommended that you use the existing tags for the topic
As you type in your proposed tag, if you pause a bit, the Answers system will search many of the existing tags and show you matches. This helps you to retain consistency with tags other people have entered. Tags that have not been applied much before will not be suggested. The details are not known, but it appears that tags will be included in the search once they have been used some 5 to 10 times.
If you have a Answers Reputation of 5 or more, then you can add tags to any Question, by clicking on the "Add/Edit Tags" link in the top right of the Tags display of Questions. This will expand the Tag area into an input area in which you can enter new tags.
If you have a Answers Reputation of 50 or more, then you can remove tags from any Question, by click on the "Add/Edit Tags" link in the top right of the Tags display of Questions, or by clicking on the red circle shown directly after the tag.