Drew up act to restrict poster (8)
I believe the answer is:
designed
'drew up' is the definition.
The definition and answer can be both related to thinking as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?
'act to restrict poster' is the wordplay.
'act' becomes 'deed' (deed is a kind of act).
'to restrict' is an insertion indicator (inserted letters are restricted or contained).
'poster' becomes 'sign' (I've seen this in another clue).
'deed' going around 'sign' is 'DESIGNED'.
Can you help me to learn more?
(Other definitions for designed that I've seen before include "Meant" , "Make a drawing or blueprint" , "Conceived of and produced 3dn" , "Planned or created" , "Conceived and drew something" .)