2.1.461 Part 4 Section 2.15.2.39, sz (Frame Size)

a.   The standard allows any string for the val attribute.

For the val attribute, Word allows an integer between 1 and 32,767 followed by *; an integer between 1 and 500 followed by %; or an integer which divided by pixelsPerInch gives a value between 0 and 22.

b.   The standard says if this element is omitted, then no information shall be implied about the size of the current frameset.

Word considers the default value to be 1*.