Using Search
"support forum"
will find all comments that contain the exact phrase support forum.
support forum
Will find all comments that contain the word support or the word forum.
+support +forum
Will find all comments that contain the word support and the word forum.
-support forum
Will find all comments that contain the word forum and which do not contain the word support.
The comparison is made against full words. The search term forum, for example, will not match forums.