Many of the Shabbat zemirot contain an acrostic of the (part of the) author's name, usually using a letter of his name at the start of each verse. For example, Y-ah Ribon has the name Yisra'el; Yom Ze Leyisra'el is Yitzhak; Akdamut has a long acrsotic at it's end, part of which spells Me'ir b'Rebbi Yitzhak.
I'm unaware if this technique was common in general (non-Jewish) poetic writing during that era. Is this unique or more frequently done in Jewish poetry? Why was this done? Was there a specific reason for embedding the author's name in this fashion, rather than just, say, putting a "signature" or some other ID so people will know who composed the piyut / zemer?