domain name system - What's the proper format for an SPF record?

Querying my domain I get:

The TXT records found for your domain are:
v=spf1 ip4:50.22.72.198 a mx:wordswithfriends.net ~all 

So superficially it appears OK. However I also get the following message

SPF records should also be published in DNS as type SPF records.
No type SPF records found.

I want to make sure things are absolutely airtight. So in addition to TXT records I also want a pure SPF record. However I cannot figure out the format. Placing the same text in an SPF record does not seem to work.

Edit:

At the moment I have a TXT record but not SPF record. When I cut and paste from TXT straight to SPF I get some type of crazy recursive DNS error so quickly deleted the SPF. I just want to know the correct format. Copying

v=spf1 ip4:50.22.72.198 a mx:wordswithfriends.net ~all 

straight into an SPF record doesn't work.

Answer

That SPF record looks correct to me, mine is quite similar to that.

Where do you get the SPF error? I checked the domain from my SPF client and it says it's okay.

You can always check the syntax here http://www.openspf.org/SPF_Record_Syntax and generate a new header here http://old.openspf.org/wizard.html?mydomain=example.com&submit=Go%21

$ spfquery -i 50.22.72.198 -m test@wordswithfriends.net -h wordswithfriends.net
pass

Please see http://www.openspf.org/why.html?sender=test%40wordswithfriends.net&ip=50.22.72.198&receiver=spfquery: 50.22.72.198 contains 50.22.72.198
spfquery: domain of test@wordswithfriends.net designates 50.22.72.198 as permitted sender
Received-SPF: pass (spfquery: domain of test@wordswithfriends.net designates 50.22.72.198 as permitted sender) client-ip=50.22.72.198; envelope-from=test@wordswithfriends.net; helo=wordswithfriends.net;