Supported mod_deflate encodings for compression

It seems to me that mod_deflate in Apache 2.2 will always return:

Content-Encoding: gzip

and never:

Content-Encoding: deflate

It was explained to me that while there might be a descent algorithm, mod_deflate is assigned a filename in a file format where the algorithm can be anything:

gzip, bzip. PKZIP

Of the three, mod_deflate provides gzip.

It seems that gzip is the most popular and widely supported algorithm in web browsers, but I know that some web servers and proxies return Content-Encoding: deflate.

Aside from the module name confusion, is it true that mod_deflate will return Content-Encoding: gzip?

Thanks.