Sometimes we want to use a keyword so other members can do a search for specific information. Those keywords are called Tags. Here's how to use them:
When you're in the message editing window (typing your message), below that window, you'll see the word Tags and below that, a rectangular box with the Select Tags button to the right. Type the word you want to use in the box below Tags, then when you're ready to post the message, click the Post button. After your message is posted, you'll see the tag below the message.

If
you want to use that tag again with another thread or another message,
instead of typing it again, click the Select Tags button and check to
see if it's listed. If it is, click the box next to the listed tag,
then click the OK button to close the Select Tags window.
As
you'll see in the second demo image above, we can add multiple tags
when appropriate for a single message or a single thread. In that case,
I typed two tags separated by a comma, Tools Palette Selectors, Brush Looks
and when the message was posted, the PainterFactory converted the comma
to a semicolin. If you type the tags, put a comma after each one. If
you use existing tags from the Select Tags window, semicolins will be
added automatically.
It's pretty self explanatory so you probably won't have any difficulty using tags.
Happy Tagging!