What’s the meaning of BUMP ? 
i think it s like up to replace the post on top of the list but not sure i m french if i m wrong please correct me!
A ‘BUMP’ is posting in an old thread simply to get that thread back to page 1 and seen by more people. If your thread is down on page 3 or 4 then it may not be read anymore. So if your question hasn’t been answered, or if the gear you’re selling hasn’t attracted any interest in a while, then a ‘BUMP’ will make the thread go back to the top of Page 1 and make it seen by more people. Sometimes people hide bumping a thread by pretending to post something relevant, but more often they will just write ‘BUMP’ to show what they’re doing.
Overusing this technique can be annoying, however!