Today we launched a larger update which includes some fundamental changes. The first one is this blog, which we opened for announcing updates and other BibSonomy related infos.
The most fundamental change is probably the generation of the hashes for publications. There are now two hashes available: a more strict one which includes entry type, title, author, editor, journal, booktitle, key and year and a broader hash which includes only title, author, editor and year in a normalized fashion. This is also described in the FAQ.
Furthermore we tweaked the layout a bit and added some hints to input boxes, which show, for example, which fields are mandatory.
Besides whitespace and the plus sign (which is converted to * automatically), every character is allowed to be contained in a tag. Especially the minus sign is allowed now.
The next improvement we are working on is a tag recommender together with enhanced tag editing functionality.