The class comment on javax.swing.text.html lists 51 CSS properties "that are suppored [sic] by the rendering engine". But if you count the number of public CSS.Attribute instances that are defined, there are 61 of them. The two lists should be made consistent. Additionally, I believe the list of properties that "are modeled, but currently not rendered" is incorrect, in that some of them *are* rendered.

An example of an attribute that is defined and supported, but not listed as a CSS property, is border-top-color.

It would also be useful to call out explicitly the rule that maps the name of a CSS.Attribute field to the name of the corresponding CSS property. I believe the rule is simply that capitals become lower-case and underscores (_) become dashes (-), but users have no easy way to know that.