Walk quietly -- possible instruction to reader in formal attire (6)
I believe the answer is:
tiptoe
'walk quietly' is the definition.
(I've seen this before)
'reader in formal attire' is the wordplay.
'reader' becomes 'pto' (I can't explain this - if you can you should believe this answer much more).
'in' is an insertion indicator.
'formal attire' becomes 'tie'.
'pto' inserted into 'tie' is 'TIPTOE'.
'possible instruction to' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for tiptoe that I've seen before include "Lightly pad" , "or get a bit higher on this?" , "Walk quietly on the balls of one's feet" , "Walk silently" , "Walk very quietly with heels raised" .)