E.g. was to modify the charge for what is in store (7)
I believe the answer is:
stowage
'charge for what is in store' is the definition.
I can't tell whether this defines the answer.
'e g was to modify' is the wordplay.
'modify' indicates anagramming the letters (I've seen 'modified' mean this).
'e'+'g'+'was'+'to'='egwasto'
'egwasto' anagrammed gives 'STOWAGE'.
'the' is the link.
Can you help me to learn more?
(Other definitions for stowage that I've seen before include "Storing space" , "Cargo area on board" .)