ContractStandards.com is a pretty useful website setup by '''Lambert & Associates''' (Boston, MA and Nashua, NH) that illustrates and explains in plain language the various clauses of a contract. For example, they have a page about [http://www.contractstandards.com/contract-structure/representations-and-warranties/intellectual-property Intellectual Property (Representation)]; calling it "one of the most heavily negotiated representations". (Note: you have to click on the "Clause Elements" section heading to actually view the contents.)
Unfortunately, they offer no example that would pertain specifically to a client using GPL software, and hiring a consultant with expertise in that software. If you look at their example '''[http://www.contractstandards.com/contracts/ica independent-contractor-agreement Independent Contractor Agreement]''' ownership is conferred 100% to the client. As in the boilerplate example, you'll likely see language from your clients about the contractor providing a "work made for hire" under the Copyright Act <ref>http://www.law.cornell.edu/uscode/text/17/201 Any "work made for hire" confers all right to the "employer" as defined in the Act</ref>. This is old-school, pre-Internet mentality and legal framework (This section of the U.S. Copyright Act was updated in 1979).
So, where can we get an idea of the language to use for a client wishing to hire a consultant who would employ GPL software and intend to publish and share that intellectual property for the benefit of the client, the contractor and the world at large?