Final answer:
A proof of execution cannot be used for documents such as wills, codicils, trusts, and certain affidavits, which require the signer to be personally present due to their sensitive nature and legal significance.
Step-by-step explanation:
A proof of execution is a legal procedure used to validate the signature on a document by someone other than the principal signer when the principal signer cannot be present to attest to the signature. This procedure is often facilitated by a subscribing witness who was present at the time of signing and can confirm the authenticity of the primary signer's signature. However, a proof of execution cannot usually be used for certain types of legal documents that require the direct presence of the signer. These documents typically include wills, codicils, trusts, and certain affidavids that are required by statute to be signed in the presence of the notary public or other authorized official conducting the notarization. The requirement for direct signature on such documents is due to the sensitive and significant legal implications they carry.