In document class book, and package caption, creating index with makeidx.
Index entries for the main text and for footnotes collate properly; but those for captions create their own entries.
Example: for the tag \index{New York!Custom House!\textit{Cartouche}}, text and footnotes collate properly; but used in a caption, a new entry is created at the third level, and is also out-of-alphabetic-sequence. Note: the top level, and first sub are correct; only the second sub is duplicated.
How to get the caption index entries under the same entry?
\documentclass{...}and ending with\end{document}. – Benedikt Bauer Dec 27 '12 at 23:14