karim said:
One example is MS Internet Explorer claiming to be Mozilla:
"Mozilla/4.0 (compatible; MSIE 5.01; Windows NT)" [other examples snipped]
Another example is Opera claiming to be MSIE claiming to be Mozilla:
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1) Opera 7.11 [en]"
These are saying they are compatible. This is different than saying I AM
that browser. Otherwise how do web servers identify the different kinds in
their logs?
No, actually, by a strict interpretation of the standards, they're all
saying they're Mozilla. The stuff in parentheses is officially a
comment. Thus, the version of IE above is saying it's Mozilla 4.0, with
a comment to the effect that it's "compatible" (whatever that means),
and that it also relates in some unspecified way to "MSIE 5.01" and
"Windows NT". The version of Opera is saying that it, too, is Mozilla
4.0, with comments of "compatible", "MSIE 6.0", and "Windows NT 5.1",
followed by a malformed product token (with a space between name and
version instead of the proper slash) saying, oh by the way, that it's
*also* Opera 7.11.