What name for bowdlerisation with asterisks (e.g., “f*ck”)?

Bowdlerization is clearly much broader in scope, as it refers to the general editing of any text to remove potentially offensive content.

The substitution of letters in profanities with asterisks or other characters was a practical solution for U.S. and U.K. publishers in the 20th century, devised to avoid the possibility of prosecution for the violation of obscenity laws.

In the U.S., 7 words were considered profane and their use forbidden in radio, television and most sorts of printed media. Those were: shit, fuck, piss, cunt, cocksucker, motherfucker, tits. These words are still not used on the major American television networks or in some publications (national newspapers such as the "New York Times", etc.).

One term invented in 1980 to describe textual symbols meant to represent profanities is "grawlix/grawlixes". Other suggestions for the same thing are "obscenicons" or "maledicta". These refer to e.g. old comic strips in which the dialog bubbles of characters sometime contain expressions like "@#*!%!", meant to represent a profanity.

See http://languagelog.ldc.upenn.edu/nll/?p=2457