How to use current standards to write a 'per procurationem' letter [closed]

After reading the Wikipedia article about procuration, I'm still confused.

Here's what I want to know:

1. What does the author mean by "the phrase per procurationem is ambiguous if used with undeclinable English names"?
2. If I sign a letter on behalf of someone, is this protocol acceptable?

   Sincerely,
   Secretary's Signature
   p.p. Account Owner's Name

Solution 1:

Forget the whole thing. Just write for followed by the name of the person on whose behalf the letter is being signed.

Solution 2:

The debate is over just how "p.p." should be used: whether before the name of the person for whom the document is signed—let's call her The Principal—or before the signature of the person who actually signs the document—let's call him The Agent

The ambiguity arises because "p.p." abbreviates a Latin phrase, per procurationem. It means, literally, "through procuration" -- in English, "by agency", (i.e. "by action of an agent"). However, this bears two different interpretations. You might write (with italics indicating the signature) either

Signed,
The Principal
p.p. (by agency of) The Agent

or

Signed,
The Agent
p.p. (by agency for) The Principal

In Latin, there would be no ambiguity, because Latin nouns are declined: they are written with endings which tell you the grammatical case. In the first example, you would write

p.p. Agentis, which is in the genitive case and tells you that it is by agency of The Agent.

In the second example, you would write

p.p. Principali, which is in the dative case and tells you that it is for The Principal.

But English names are not declined, so there's nothing to tell you who is The Agent and who The Principal and which one signed it.

The important thing is to avoid ambiguity; so I would avoid using p.p. at all. There are lots of options out there; here's the one I used when I was office manager at a law firm:

Signed,
StoneyB
for MyPrincipal, Esq.

Solution 3:

“The phrase per procurationem is ambiguous if used with undeclinable English names” refers to a difference between English and Latin in the treatment of names. Consider the example

Praeses
per procurationem Secretarii

Praeses is nominative singular and means protector, guard, guardian, defender, or head, chief, ruler. Secretarii in this instance is genitive singular of secretarius, meaning secretary. Thus, “per procurationem Secretarii” unambiguously means “through the secretary's agency”, by dint of secretarius having been declined from nominative singular to genitive singular secretarii. Since English does not provide for such declension, use of p.p. in a similar instance in English would leave it undetermined whether the Chief signed on behalf of the the Secretary, or vice versa.

Addressing one other point in your question, the debate is about which name should have p.p. placed before it, when writing in English. As to whether p.p. protocol is acceptable, see other answers and comments following question.