The New York Post is reporting that CBS rejected a television commercial for Thinx because of the way that it depicts men menstruating.  Thinx sells reusable underwear that can be worn during menstruation as a substitute for pads, tampons, and other products.   

The new commercial from Thinx imagines what the world would be like if men also got their period.  The commercial shows a boy telling his dad that he got his period for the first time, a man asking another man for a tampon on the way to a meeting, and other situations faced by women.  The commercial ends with the lines, "If we all had them, maybe we'd feel more comfortable with them" and "It's time to get comfortable."  

CBS was, in fact, not comfortable.  The two aspects of the commercial that apparently raised concerns with the network were a scene where a man was shown leaving a blood stain on a bed and a scene where a tampon string is shown hanging out of a man's underwear in the locker room. 

CBS's decision here is no big surprise.  Menstruation has long been a sensitive subject for network television -- with the networks setting very specific standards about what can and cannot be shown (such as no blood and no tampon strings).  Although networks have certainly become more flexible about what they'll allow to be shown, clearly there's a line (or string) that advertisers can still not cross, at least on some networks. 

What's this all about?  Each television network -- like any other media outlet -- generally has the right to set its own standards for what is acceptable for airing.  Often, network standards focus on issues like ensuring that advertising claims are truthful and that disclaimers are up on screen for a sufficient time for them to be read.  Networks (and others) also have restrictions on when some products can be advertised and prohibit the advertising of other products completely.  The networks, who are considering their own brand image, their relationships with their audience, and their perceived responsibility as a broadcaster -- also reserve the right to reject advertising on taste and any other grounds that they see fit.  

According to the Post, after its story ran, CBS did ultimately agree to accept another version of the commercial.