Onan the Clumsy,
It looks like the option to post using HTML has been disabled in these forums. (It is something that the Admin turns on in the Forum Setup.)
There is a
Normal Mode and an
Enhanced Mode under
vB Code, you could give that a shot and see if it helps.
Take Care,
Richard
P.S. I think I remember there being a Test Forum when PPRuNe first switched over to vBulletin, I think it was for testing problems from the changeover or something like that. I am sure the mods will be able to give more info.