Frame guides showing ways to access multiple places (8,4)

I believe the answer is:

skeleton keys

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'ways to access multiple places' is the definition.
I can't tell whether this definition defines the answer.

'frame guides showing' is the wordplay.
'frame' becomes 'skeleton' (synonyms).
'guides showing' becomes 'keys' (I am not sure about this - if you are sure you should believe this answer much more).
'skeleton'+'keys'='SKELETON KEYS'

Can you help me to learn more?

(Another definition for skeleton keys that I've seen is " versatile openers".)

I've seen this clue in The Independent.

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