Ooo wow. Rhotacism! Cool word. Thank you for it. To use it in a sentence, I had known a friend for years before realizing he displayed rhotacist tendencies. Except that it was with ell, not arrr. Ergo, probably a different word. Can't help me with that one, can you? I'm taking Bly on faith when I call it a translation. However, I suspect there may be a much deeper conflict of definition here. So, I must ask, what to you would distinguish a version from a translation?
If the process deals with /l/ then it's something called "gliding of liquids". Anyway, a rhotacism is the general process of producing a hard /r/ while non-rhotic dialects would for example (in American English) be the New English accent and most British English dialects. The dialogue in terms of Rumi is that in the dialect of Persian he wrote in is often not translated directly, that is the "translations" are approximations of what the translator understands the tone and diction of the original text to mean. A version would be such an interpretation. I can't read the language Rumi wrote in and I wonder how faithfully Bly and others have reproduced it, especially since so Rumi is such a popular poet these days. Anyway, good post.