Controls VSS's use of the read-only flag for files that are not checked out.
Use_ReadOnly = {Yes|No}
Flags local copies of non-checked-out files as read-only:
Use_ReadOnly = Yes
By default, VSS assumes the files in your working folder that you do not have checked out that is, files you should not be modifying are read-only. VSS sets the read-only flag when you get, add, check in, or undo check out of a file, and uses it as a signal that you have not been modifying the file (so VSS can overwrite it). If you set this variable to No, VSS does not set the read-only flag on files in your working directory.
You can also set this variable in your SS.INI file by using the Use Read-Only Flag for Files That Are Not Checked Out option on the Local Files tab in the SourceSafe Options dialog box.