Comment 25 for bug 633742

Instead of transforms, there's already an excluded character
list in version comparison. All excluded characters are treated
equivalently (originally, and still in @rpm.org code, all "other"
punctuation characters are treated equivalently: so
    1.2_3 = 1.2|3

See rpmdb/rpmevr.c (where the comparison routines live)
for two quirks:

/* XXX Force digits to beat alphas. See bugzilla #50977. */
/*@unchecked@*/
#if defined(RPM_VENDOR_MANDRIVA) || defined(RPMVERCMP_DIGITS_BEAT_ALPHA) /* old-comparision-behaviour */
static int _invert_digits_alphas_comparison = -1;
#else
static int _invert_digits_alphas_comparison = 1;
#endif

/* XXX Punctuation characters that are not treated as alphas */
/*@unchecked@*/ /*@observer@*/
static const char * _rpmnotalpha = ".:-";

Unless you need to handle "branding" in release with the expectation of "newer",
don't do what Mandriva is doing.

And add any characters you wish to the excluded character _rpmnotalpha list.
The far harder issue (which likely necessitates awkward/complex transforms always)
is tools like zipper not using rpmlib API calls for version comparison.