How to Find Relevant forum- SEO tips

some of the footprints I use would be :

“powered by vbulletin” "Your Keyword"
“powered by yabb” "Your Keyword"
“powered by ip.board” "Your Keyword"
“powered by phpbb” "Your Keyword"
“powered by phpbb3″ "Your Keyword"
“powered by invision power board” "Your Keyword"