What does beneficiary “sign off” of the estate accounts actually mean?

[dslippy]

The earlier versions of Word did have a supposed ability to mark amendments, but I could never get it to work.

Rod929,
You are almost right about the signing of an amended document, but it might at worst be impolite. If you want a change, agree it with the other side, or waste everybody's time.
Some amendments are trivial - correcting of spelling mistakes.