Shibboleth

compare https://en.wikipedia.org/wiki/Emotive_conjugation

  I am accommodating
  You are using shibboleths
  They are dog whistling

EDIT: reflecting on שׁ‎ not being a difficult sound for english speakers, I'd thought כ was pronounced differently to ח‎, but a cursory search reveals there are many communities where they're homophonous.

Also an unpleasant piece of software.