I recently asked someone why they had several instances of "&c" in their writing, to which they told me that &c is another abbreviation for et cetera. I have since looked it up and understand now where this comes from, with the "&" being more than just an "and" symbol, that written correctly it is actually based on, and looks like, "et".
Apparently some people have used it this way before, but "some people have done it, especially in the past" makes it neither correct nor accepted in general. One site I came across in my research on this even states that you should not do this.
Finally, ‘etc.’ should not be written with an ampersand instead of the ‘et’ part (&c) except when an older source is being duplicated or transcribed.
That is from a description of when to use etc. from proof-reading-service.com
Is "&c" a correct way to abbreviate "et cetera" in English? Or was it a temporary slang term, similar to "aint", but which never caught on and is used to be quaint?