${^B\!}f_i$
which describes a vector in the frame {B}. I declare the symbol to nomencl with
\nomenclature[yx ]{${^B\!}f_i$}{Vector $f$ in \{B\} frame}
.The problem is that nomencl seems to misinterpret the "\!" (which reduces the space between the index and the symbol) as a subitem or something, as the main.nls shows:
\item yx ${^B\ \subitem [{${^B\ \subsubitem } f_i$}] \begingroup Vector $f$ in \{B\} frame\nomeqref {\relax 4.7}
Any ideas how to fix this?