On Yom Kippur we mention that the high priest said the "shem ha-meforash"
According to Rambam this is the the four letter name consisting of a
"yod", "heh", "vav", "heh" with the proper pronunciation (others claim it is
one of G-d's names with 42 or 72 letters). This was pronounced only in the
Temple by the priests. As such I heard from Rav Soloveitchik Zt'l that
one is not allowed to prononuce the name "J. witnesses" since their first name
is an approximation to the "shem ha-meforash"
Just as an aside the phrase "shem ha-meforash" in the davening is
explained
as either G-d's proper name or else that G-d's name came out explicitly
from the high priest so that "meforash" is not an adjective describing the
name but rather a verb describing how it came from the High priest's mouth.
Eli Turkel turkel@math.tau.ac.il