We've had this fight on Code4Lib before, but it deserves mentioning
that no browser breaks this, and no browser developer is going to
break it. It's widely used—for more widely used than any number of
"standards-compliant" techniques that don't work and probably never
will. To care about this in the context of today's mainstream OPACs is
like keeping your fingernails clean after a nuclear attack.

>  I would not recommend this because it is not standards compliant. W3C
>  standards reserve only four names for the target attribute "_blank",
>  "_parent", "_self", and "_top".  Some developers also use "_new" instead
>  of "_blank" as the value for the target attribute to open a link in a
>  new window, although W3C standards do not define that as a target name,
>  thus browsers may ignore it or treat it as a synonym for "_blank".
>  Browser settings can override all of this.