Hi, you can see at the top of your post here where its been posted English forum / Community / 
Boost your lustibg/search/ guestpoints.
English forum / Community = one of the main categories of the 4 on the first forum page
Boost your listing =thread chosen in community category
guestpoints = a tag
Hiw to boost your listing ( just a reminder, the forum is public and is open to members and non-members of HE. The alternative is just to post your listing id number accessible only to HE members)