One page, one file. Save one file per sheet writes every page of the set as a separate single-page PDF. It does not group pages, and there is no page-range or discipline filter, so a 90-page set becomes 90 files. A page without a title block, such as a specification page bound into the set, is still written; its row is flagged, and unless you type a sheet number its file name starts with Page and the page number.
The name. Each file is named with the sheet number, a spaced hyphen and the sheet title, then .pdf: A-101 - FIRST FLOOR PLAN.pdf. Names come from the review table, so whatever you typed in a cell is what the file gets. The Revision column is there for checking and is not added to the file name.
Windows-safe names. A slash, colon, question mark, quotation mark or other character Windows does not allow in a file name is replaced with a space, repeated spaces are collapsed, and names Windows reserves for devices, such as CON, get an underscore. Very long titles are cut so the name stays within 120 characters before the extension.
Collisions. Two pages with the same sheet number are flagged in the table before you export. If you split anyway, the later page gets its page number added, such as (page 41). If the destination folder already holds a file with the same name, for example from an earlier split, Windows gives the new file a different name and the existing file is left alone.
What is inside each file. Each split PDF holds the page as it was drawn, at its original sheet size, with one bookmark carrying the sheet name. The document title, author, subject and keywords of the source are copied. The source's existing bookmarks, links and layer settings are not carried over, and split files carry no page label.
If something stops the split. When Windows refuses a write part-way, for example because access to the folder is denied, SheetStamp stops, removes the unfinished file, and tells you how many files were written. Fix the cause and run the export again.
Check first. Text recognition can misread a sheet number, and a misread in the usual spot is only flagged when it duplicates another sheet. Read down the Sheet column under All pages before splitting, because the file names are only as good as that column.