Hi

I've been asked to add a rule to a daily checklist whereby only the user can enter their initials to sign off a task i.e. only I can enter my initials, no-one else can do it intentionally or unintentionally. Previously I'd been using a simple list but then we can each choose each others initials.
I figured as Excel knows our usernames, there must be a way that it knows if we're entering someone else's name/initials.

Any ideas?
Thanks
Clare