Lately, I've been seeing many people wearing yarmulkas that say:
נחמן מאומן - (Rav) Nachman, the trained
I think we can assume that Nachman was trained to be a rav. Even if he was trained in other things, why does that need to be publicized on a yarmulka?
You forgot the first part of the quote:
ננח נחום נחמן מאומן
נח of course is a euphemism for death, as in the phrase in various Gemaras נח נפשיה.
The term אומן is reminiscent of two quotes from Kiddushin. The first is its final Mishnah:
רַבִּי נְהוֹרַאי אוֹמֵר, מַנִּיחַ אֲנִי כָּל אֻמָּנוּת שֶׁבָּעוֹלָם וְאֵינִי מְלַמֵּד אֶת בְּנִי אֶלָּא תוֹרָה
Rebbe Nehorai said: I put aside all trades in the world, and I only teach my son Torah.
The second is a Braisa on 29a:
רבי יהודה אומר כל (שאינו) מלמד את בנו אומנות מלמדו ליסטות
R’ Yehudah says, whoever teaches his son a trade teaches him thievery.
(Many readings include שאינו in this teaching; Haghos HaPurim Rav takes it out.)
What we see here is that being trained is a bad thing.
Now, what kind of training did נחמן have? Well, apparently his full name was נחום נחמן, and, as we know, נחום was a candle maker whose candles are forbidden for Shabbos candles.
Seemingly, these yarmulkes are warning others: don’t be trained in a trade. After all,
ננח נחום נחמן מאומן
Nachum Nachman, the trained, died.
נחמן מאומן may be roughly translated to the trained psychologist, or comforter. The message on the yarmulke refers to the fact that although Ukraine is not yet covered under EuroPsy (or European Certificate in Psychology), he is still certified in one of their other two dozen or so covered countries.
