The new R-Card allows teenagers to see “R”-rated movies without an adult. But “the problem with the R-card is that all R-rated movies are not equal. The rating has been assigned to movies as diverse as the charming “Billy Elliot” (theatrically released as an R for bad language and brief sexual references, but later edited for a PG-13 on video) and the ultra-violent “Kill Bill” (rated R for constant carnage as well as strong language and sexual violence).”