HMRC internal manual

Company Taxation Manual

Authorised investment funds (AIFs): taxation of funds: capital gains

You should check the other guidance available on GOV.UK from HMRC as Brexit updates to those pages are being prioritised before manuals.

CG not chargeable

Capital gains of authorised investment funds are not chargeable gains - see TCGA92/S100 and the exception to TCGA92/S99 (1) (both as modified by SI2006/964 Regulation 100).