Could some one please tell me how i can make spoilers for like a clan desc?

How to make spoilers:

Step 1: When posting a reply or thread, click "go advanced"
Step 2: after clicking that, in the top right there is something that says "spoil"
Step 3: then type what you want to title of the spoiler to be in the pop up window
Step 4: after that, inbetween the to spoil tags type what you want in your spoiler.
Step 5: Your done.

^too much steps
step 1: write: [spoiler=spoiler name] Inside content [/spoiler]

and its done

So lets say achievements. Since there all on the desc all i have to do is put inside content achievements and it will work?

Yes.

Alright thanks for your help.