2.1.410 Part 1 Section 17.15.1.59, noLineBreaksBefore (Custom Set Of Characters Which Cannot Begin A Line)

a.   The standard does not state how conflicts between this element and the strictFirstAndLastChars element should be resolved.

Word ignores this element when the strictFirstAndLastChars element is also specified.

b.   The standard does not limit the length of the value of the val attribute.

Word restricts the value of this attribute to be at most 100 characters.