W3C SpecificationCSS2.1
Thedisplay property is extended with the following values by CSS2.1:
tableinline-tabletable-row-grouptable-header-grouptable-footer-grouptable-rowtable-column-grouptable-columntable-celltable-captionAdjacent borders of cells can be made one border thin using theborder-collapse property, like "border-collapse:collapse;".
The spacing between the borders of cells can be set using theborder-spacing property, since CSS2. The setting of the property has no effect if borders have been made look one border thin using "border-collapse:collapse;".