What to include in CG calculation attachment

[FigNewton]

Rather than use the worksheets, I need to create my own attachment. But what should I include? The HMRC pages are mute. There must be an acceptable form in which to create an attachment.

Suppose I sell shares in a US company in which I have bought shares at various times over many years. Do I need to show for every composite of my Section 104 holding the purchase date, price, cost, and fx rates that I used at each purchase date to convert cost to GBP? and hence how I arrived at my GBP per share average cost price.

Or can I just give just a date of sale, # shares sold, cost (based on GBP per share average cost) and proceeds in GBP?