Documentation of the data for SketchPostscript.

All pages beside the last (back) have a base file named pad<pagenumber>.sst.
The back has the name pagback.sst
Some pages have one datafile named dat<pagenumber>.sst
Some pages have several datafiles named dat<pagenumber><a letter from $a to $z>.sst

Some pages has in the base file dummy figures to be used for placing the data.