From
Pentax Lens Terminology
*: the star sign follows the lens series designation (e.g., A*, FA*), and denotes a high-performance lens that uses special-glass elements.
If you have not seen a DA* lens, the star is the classic Pentax red color.
These days it's not the best specifier for lenses as others have mentioned. It's difficult for the Internet to handle and confusing to people who don't know Pentax.
Originally posted by Gary G Thanks for everyone's feedback to my question. After reading everyone's take on the meaning of *ist, I find comfort in the knowledge that I was not missing something that was obvious to everyone but oblivious to me. I'll go with the answer that Pentax attempted a clever marketing gimmick that at the time may have looked good on paper, but....... ! And here I thought making sense of all the various letters associated with lens descriptions would be my only frustration in digital photography. Now this comes along....