transliteration

Yes, but at this point it's pretty well established in many words that have been naturalized. I tend to use the YIVO romanization scheme (link). It's the most widely used academically and lexicographically.

[Addendum: Looking 'round the YIVO site, I see that they have published a complete English translation of Max Weinreich's masterful History of the Yiddish Language. For anybody interested in Yiddish linguistics it's a must-have. Now I know what I want for nitl.]

Ceci n'est pas un seing.