Dictionaries normally include the first word on the page in the header on 
the upper left and the last word on the page in the header on the upper 
right. I am calling these the guide words. Open office has a field code for 
chapter that allows a paragraph style to be specified and the contents of 
the paragraph with that style will be included in subsequent headers. This 
feature would be implemented with another field code that allowed the user 
to specify a character style and whether the first or last element of that 
style on the page should be used. (Similar to StyleRef in Word) Thus unlike
chapter, the first (or last) sequence of characters marked with this style on
the current page would appear in the header. (Note that some dictionary entires
are more than one word.) Some words will also have a homophone number after them
(usually superscripted or subscripted). Presumably if such a field code existed,
a second instance could be used to capture the homophone number on the first or
last entry (if there was one) and put it in the header. (Likely the formatting
of the homophone number would be like that in the entry and frequently the
homophone number on the first or last entry would be non-existant.