In earlier versions of A-Shell, literal N and n characters in PRINT USING MASK expressions were being misinterpreted as numeric fields. To avoid this, N and n are now ignored as possible leading numeric field indicators unless immediately preceded by a non-alphabetic character, and there are no alphabetic characters other than N to the right, all the way to the end of the mask. For example:

PRINT USING "Neg. scans: NNN", X

PRINT USING "Neg. scans: NNN (total)", X

PRINT USING "Neg. scans: #nn (total)", X

In all three statements, the "N" in "Neg." and the "n" in "scans" are treated as literals, since they are adjacent to alphabetic characters.

In the first statement, the "NNN" acts as a mask, because there are no subsequent non-alphabetic chars. In the second, the "NNN" is treated as a literal, because of the trailing alphabetic chars in "total". In the third, the "#nn" is treated as a mask because "#" is an unambiguous leading mask character.

Note that this limitation effectively disables the use of the leading "N" and "n" mask characters in PRINT USING MASKs containing trailing text, but it doesn't affect the use of "N" or "n" as trailing mask characters (e.g. "##.nn"), and doesn't generally affect the common case of <VALUE> USING MASK expressions unless they contain trailing alphabetic characters, which is odd but legal.