🚧
This will not delete the tag for other contacts
This call will only remove the tag on the individual contact.
For example, "John Doe", a contact with and id of 6 has the tag "foo," and that tag has the id of 11.
When the tag id foo is placed on John Doe's contact, an "association id" is created, id 22.
A DELETE call to /contactTags/22 will delete the association of "John Doe" and the "foo" tag. It will not delete the "foo" tag for other Contacts, only for "John Doe," because the association between the tag and the each other Contact will have a different association id.

📘
Retrieving a contact's tag id's
The correct tag association id necessary for this call, and can be retrieved with a GET request to /api/3/contacts/:contactId/contactTags