The Sulfhydryl reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Sulfhydryl

Helping orphans the way you would do it
Sulfhydryl, also called thiol, is contained in a reduced state within coenzyme A, lipoamide, glutathione, cysteine, and mercaptans.

The listing for sulfhydryl is denoted as -SH. The above would be listed as R-SH. Radical -SH.

Sulfhydryl also has applications in Molecular electronics.