Chinese traffic with disallowed key characters

[eluser]Unknown[/eluser]
I have a reoccurring issue where non-malicious users from China get flagged for disallowed key characters in the $_COOKIE array. I have narrowed it down to a cookie that follows this format:

1383227545|8554573|60519|0|0|0=1383227545|8554573|60519|0|0|0 (cookie name = cookie value)

My question is not why (for those that don't know, the disallowed character is the pipe '|') but what...what is that cookie? It only appears occasionally with Chinese users, specifically around Hong Kong, and it seems to happen mostly with SSL pages. Is this some sort of tracking cookie for the Chinese government? It looks an awful lot like a UTM cookie value

I know that I can add the pipe as an allowed character as the character by itself doesn't pose any security issues, but I'm mostly curious of the implications of allowing such a cookie or if I am completely off-base with my assumptions about the cookie itself (i've looked all over the webz and can't find anything about a pipe delimited chinese tracking cookies)

any help is already appreciated!