I think this might be more of a wiki enhancement than a product enhancement. I haven't gotten around to documenting how the spell check works, but only because I don't really understand it myself yet - and that's because I don't use it.
The following are info and links that are related to the spell checker used in ToDoList. I'm hoping folks can help me by providing other links and detail that can be used to pull together a base of information for a nice wiki page on this topic.
The MySpellCheck.dll used in ToDoList comes from MySpell, a utility created back in 2002. Rather than extending functionality for this, the next best step might be to replace it.
https://en.wikipedia.org/wiki/MySpellhttps://wiki.openoffice.org/wiki/Writer/HallOfFame ... MySpell extended to become Hunspell
https://en.wikipedia.org/wiki/Hunspellhttp://hunspell.sourceforge.net/http://sourceforge.net/projects/hunspell/files/Hunspell/Documentation/ ... summary and lower-level info
The PDF docs on that page are probably the best available.
http://www.openoffice.org/lingucomponent/ ... how to create dictionaries
http://fmg-www.cs.ucla.edu/geoff/ispell-dictionaries.html ... MySpell is based on ISpell and a Lot of dicts are here, including recent updates
So.. here is ISpell:
http://fmg-www.cs.ucla.edu/geoff/ispell.htmlhttp://fmg-www.cs.ucla.edu/geoff/ispell-man.html ... "man page" describes ispell command line and a lot of insight into features
But that's only the primary man page, the complete set of man docs come with the ispell distribution package, which should be available on any Unix system where it's installed. I downloaded the source for ispell but did not find the man pages in there, though there are a number of dicts modified as recently as Feb/2015.
This is an ISpell Affix Table, with a lot of good doc notes:
http://www.openoffice.org/lingucomponent/english.affThis is a MySpell Affix table, similar but very different:
http://www.openoffice.org/lingucomponent/en_US.affGreat notes on the structure of the MySpell Affix file:
http://www.openoffice.org/lingucomponent/affix.readmeAs to adding words to your local files, there are various utilities in Perl or PHP or .NET, etc which use other libraries for maintaining these files. A UDT can be created which pops up a box to enter a word that should be added to the dictionary. I have no idea at the moment about the details for how this would be done, but as a developer I can mentally connect the dots, and I know it's possible. With more info here perhaps we can come up with such a tool outside of ToDoList which can be used by anyone who is looking for this functionality.