In Calc, if there is a word improperly marked as a misspelling, I want to add it
to the dictionary so the false positive doesn't show up anymore.  I right-click
the word and click "Add".  It pops out a menu with several options:

    soffice.dic
    sun.dic
    IgnoreAllList
    standard.dic

I am a technical user, and I have no idea which option I should select.  A
non-technical user would just be lost.

Instead, the context menu action should be more explicit, like "Add to
dictionary" or "Word is spelled correctly" or "Not a misspelling".  

If there is only one logical choice for the dictionary, then there should be no
sub-menu.  Clicking "Add to dictionary" should just add it to the user's custom
dictionary.

If there is a choice to be made, it should be stated in a clear way.  If there's
a difference between a user's custom dictionary and the system-wide custom
dictionary, for instance, the sub-menu choices could be phrased as "Add to my
dictionary" and "Add to dictionary for all users".