indexentry — An entry in an index
indexentry ::=
primaryiesecondaryieAn IndexEntry wraps all of the index terms associated with
a particular primary index term.  This includes an arbitrary list of
secondary and 
tertiary elements as well as 
See and
SeeAlso elements.
Formatted as a displayed block. A rendered index usually places secondary items under primary items and tertiary items under secondary.
The following elements occur in indexentry: primaryie, secondaryie, seealsoie, seeie, tertiaryie.