Index sorting options Latin Script/Hungarian missing letter "Ny".
It has the @Hungarian letters "Gy" and "Ty", but is missing "Ny".
Also accented pairs are supposed to be alphabetized together:
However they are listed separately. The workaround currently is to use the Sort By field in the Topic Options. And once the Index is generated, list "Ny" manually under its own heading.
I wonder if there is a fix available for this for CS5.5 and above.
Have you reported this to Adobe? It might be a bug that's been fixed in later versions, but if it's not been reported the engineering team might not be aware of it.
You can report a 'bug' via Wishform - Adobe InDesign
Thank you for this. No, I have not, but now I did!