What word describes a person who signs an official document?

For example, I have a document that has the signatures of three people, all public servants: a tax collector,an inspector, and a school principal. How could I collectively describe these three people?

This entry offers signatory but it implies a party to a contract.

(Props to @JLG for making me look this up.) Signatory need not refer simply to a party in a contract. While some dictionaries define it that way:

NOAD: a party that has signed an agreement, esp. a country that has signed a treaty

Collins English Dictionary (via Dictionary.com): person who has signed a document such as a treaty or contract or an organization, state, etc, on whose behalf such a document has been signed

Cambridge Dictionaries Online: a person, organization or country which has signed an agreement

Oxford Dictionaries Online: a party that has signed an agreement, especially a state that has signed a treaty: Britain is a signatory to the convention

Others define it more broadly.

M-W: a signer with another or others signatories to a petition; especially : a government bound with others by a signed convention

Random House Dictionary (via Dictionary.com): a signer, or one of the signers, of a document: France and Holland were among the signatories of the treaty.

Wikipedia: The writer of a signature is a signatory.

Notice, however, that these last three seem to be more layman's dictionaries than comprehensive ones. In light of this, it would seem that it is all right to use signatory in informal or non-official usage, but that a better word might be needed for official use.

_{Disclaimer: I am not a lawyer.}

Why not signers, as in the signers of the Declaration of Independence?

Many dictionaries suggest the use of signee.

NOAD and Oxford Dictionaries Online: a person who has signed a contract or other official document.

M-W (sign): a : to affix a signature to : ratify or attest by hand or seal sign a bill into law, sign a confession b : to assign or convey formally signed over his property to his brother c : to write down (one's name) d : to affix one's name to a signed review

Dictionary.com (quoting the Random House Dictionary): a person who signs a document, register, etc.; signer; signatory: a signee of the declaration of independence.

_{Disclaimer: I am not a lawyer.}