added.txt not being picked up

I’m trying to add a proper noun to a document. In added.txt in /org/languagetool/rules/en/en-NZ I’ve added:

Bovis Bovis NNP

(tab separated), but running
java -jar languagetool-commandline.jar -l en-NZ test.txt
I get:
1.) Line 1, column 17, Rule ID: MORFOLOGIK_RULE_EN_NZ prio=-10
Message: Possible spelling mistake found.
Suggestion: Boris; Bois; Ovis
This is a test, Bovis.
^^^^^
What am I missing?

added.txt only works for the part-of-speech tagging for most languages. To add words so the spellchecker accepts them, you need to add them to spelling.txt.