in your behalf?

[GSCole]

Ron,
Generally, a letter written 'in behalf' of someone is not solicited.  In
a letter of reference, the phrase indicates that someone took time to do
something for which there was not otherwise an obligation, i.e., the
author had not been asked to write a letter of reference.  I usually
think of such reference letters as being 'positive', but I guess that
unsolicited negative letters of reference could also be seen as being
'in behalf' of someone.

A letter written 'on behalf' of someone is one which is written either
at the request of that someone or it was solicited because the author
was on a list of references, i.e., the author had otherwise agreed to
write a letter of reference.

Thus, a recipient's evaluation of a letter of reference would include
attention to the presence of the phrase:  'in behalf of' or 'on behalf
of'.

The above relationships are ones that I was taught, decades ago, in a
Business English class, at a 2-year college.  I defer to the judgment of
the members of this list, as to the existence of a difference in the
above phrases, i.e., I'm here to learn, and not to get ticked off.

George Cole
gscole at ark.ship.edu
Shippensburg University
[As the members of the language programs at Ship may be quick to note,
I'm not a member of their department.]