The anonymity available to editors on Wikimedia Foundation projects is, I agree, an inherent component of those projects and we have recognised that such a request may be made of the Chapters too.
Being a member of the *Chapter* will be open to all ages and can be under a pseudonym / handle. We do not envisage that the list of members of the *Chapter* will be a public document.
In essence, however, for someone to be a registered member of the *company* that is subject to the Companies Acts - The Regulations in Table C in the Schedule to the Companies (Tables A to F) Regulations 1985 - and will require the real full name and address of the individual member on the list of members which is legally required to be held.
That list is a matter of public record, however there are procedural requirements to access that list which should preclude most 'antagonistic' issues. Similarly, such a list will not hold details of someone's pseudonym / handle thus matching those will be impossible.
Whilst some sort of nominee approach is possible for a shareholding in a company with an issued share capital it doesn't work for a company limited by guarantee where members do not pay up front for shares but contract to pay a limited sum in the case of the Company being wound up. The Memorandum of Association sets the limit on that sum as £1.
I hope this clarifies the situation.
Alison Wheeler Chair, Wikimedia UK