Did you know that, per WP, investment funds, managed funds, mutual funds come under the head of "collective investment scheme"? I did not. I still do not know what exactly comes under the head, which is why I think the head is worth having a definition. Anyway, here comes a quotation that suggests a need for a definition, even if not the present definition:
2003, Jonathan Fisher, Jane Bewsey, The Law of Investor Protection:
The definition of primary importance is of course the definition of "collective investment scheme" itself. That is to be found in s.235 of FSMA 2000.
Looking at Google books shows further occurrences of "collective investment scheme" that suggest that the phrase is a set one, with a meaning that can decide the result of a trial at a court.
Some of the Google books actually define the term.
Keep under the emerging inclusion of (or re-emphasis on) the "legal definition" criterion for inclusion as an idiom (Item 4 on our rendition of the Pawley list). See #ground beef, WT:BP#Legal definitions.. DCDuringTALK 18:18, 12 June 2009 (UTC)
No consensus: kept.—msh210℠ 21:35, 2 August 2009 (UTC)