Pleased with notes about keys and container (9,3)
I believe the answer is:
gladstone bag
'container' is the definition.
(Gladstone bag is an example)
'pleased with notes about keys' is the wordplay.
I cannot quite understand how this works, but
'pleased' could be 'glad' (similar in meaning) and 'glad' is present in the answer.
an anagram of 'notes' is 'stone' which is located in the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'and' is the link.
Can you help me to learn more?
(Other definitions for gladstone bag that I've seen before include "Large old portmanteau" , "case" , "Briefcase-like container" , "hand luggage" , "Small portmanteau" .)