Page about having registered fruit (5)
I believe the answer is:
grape
'fruit' is the definition.
(grape is a kind of fruit)
'page about having registered' is the wordplay.
'about' indicates an anagram.
'having' indicates putting letters inside.
'registered' becomes 'R' (abbreviation, as in registered trademark).
'page' anagrammed gives 'gape'.
'gape' placed around 'r' is 'GRAPE'.
(Other definitions for grape that I've seen before include "It grows on the vine" , "Pager (anag.)" , "Vine fruit" , "Vine berry" , "Small fruit; type of shot" .)