The format is described in the TeXBook but in short .\hbox(7.71974+2.25569)x360.0,
is a box of height 7.71974pt, depth 2.25569 and width 360.0pt nested one level inside some other box ....\hbox(0.0+0.0)x17.0 is a box of height and depth 0 and width 17pt (it will be the indentation box) that is nested 4 levels deep from the outer page box. -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
