Custer pops out for outline of plan (10)

I believe the answer is:

prospectus

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'outline of plan' is the definition.
'prospectus' can be an answer for 'plan' (thesaurus). I am not sure about the 'outline of' bit.

'custer pops out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'custer'+'pops'='custerpops'
'custerpops' is an anagram of 'PROSPECTUS'.

'for' is the link.

Can you help me to learn more?

(Other definitions for prospectus that I've seen before include "Promotional booklet" , "University entering opportunities for success in brochure" , "Advertising booklet for school or university" , "Programme" , "Brochure giving details of college courses etc" .)

I've seen this clue in the Sydney Morning Herald.

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