All files modified by the WHPO/SIO will carry a version number, so that the most recent files may be readily identified. The format for this version number, which will occur at the top of the file (and will not violate any predefined format described in the 90-1 manual) is:

19980128WHPOSIOJHS

where:

• "1998" the 4-digit year of modification
• "01" is the 2-digit month " "
• "28" is the 2-digit day " "
• "WHPO" the organization where the modifications took place
• "SIO" the institution where the organization resides
• "JHS" the initials of the person who modified this file