No. No. NO! Who's bright idea was it to construct this malformed Accept-Language?

• en-US,en;q=0.7,chrome://global/locale/intl.properties;q=0.3

"chrome://..." is neither a language tag (per RFC 3282) nor CFWS (per RFC 2822) *grumble*

And where does this originate from?

• en-securid

It isn't registered in IANA's language subtag registry. The owner should use either x-en-securid or en-x-securid. *grumble*

Currently debating the merits of inferring the country when the language tag is composed of a primary subtag only (e.g., no region subtag). Reading: RFC 4646, RFC 4647