The One True Wiki[0] says "Used to describe an implementation that needlessly relies on strings when programmer & refactor friendly options are available."
Which is exactly what's going on here. A username has a string as a payload, but that payload has restrictions (not every string will do) and methods which expect a username should get a username, not any old string.
Which is exactly what's going on here. A username has a string as a payload, but that payload has restrictions (not every string will do) and methods which expect a username should get a username, not any old string.
[0]: https://wiki.c2.com/?StringlyTyped