The socket server is fairly common in the industry but has a few local variations.

Care to elaborate upon the type of socket server you are connecting to?

I have just come across one variation that seems to split the socket response over two lines, which seems strange.

There nothing particularly unusual about a response covering multiple lines. Think about a webserver which a single line get usually results in 100s or 1000s of lines of response. Or an ftp get which fetches whole files as the response.

It all comes down to the specified (or just agreed) protocol for the type of server. Either the specification allows multi-line responses -- in which case your client should expect and handle them -- or it doesn't -- in which case you've found a non-complient server and should probably report the problem to the owners.