Problem related posts / %title%

hi,

i got this function concerning related posts :

php STP_RelatedPosts(‘ %title% ‘); ?

as you can see i do use a lot %title% to create my href.

My problem is that i’d like to use the Post Id of my post as a variable but it doesn’t work.

what i’d like :

//?php STP_RelatedPosts(‘ %title% ‘); ?//

could you please explain me why %title% (that i do not even find in the codex) works perfectly and the other “structure tags” are inefficient ???

Is it magic ?

Thanx a lot for your answers

Alex