Contributors to ASF projects already have an Individual Contributor
License Agreement (CLA).

If your employer allows you to contribute material which was
created during work time using work-related resources, then
please note that from your point-of-view you might need to file
a Corporate Contributor License Agreement (CCLA) with The Apache
Software Foundation.

Employment contracts are different for each individual case.

Also in some countries the employer might have the rights to
anything done outside work hours. Amazing, but there you go.

So the responsibility is yours to know when you need a CCLA
to CYA.

[1] http://www.apache.org/licenses/#clas

[2] The current clarification at Apache Incubator:
http://marc.theaimsgroup.com/?t=113933318900001

-David