De or het spellingherziening?

The correct Dutch article is:

de spellingherziening

Rule Words ending in -ing: almost always de. See the rule

How to use spellingherziening

the spellingherzieningde spellingherziening
this spellingherzieningdeze spellingherziening
that spellingherzieningdie spellingherziening
our spellingherzieningonze spellingherziening
your spellingherzieningjouw spellingherziening
every spellingherzieningelke spellingherziening
which spellingherziening?welke spellingherziening?
a big spellingherziening / the big spellingherzieningeen grote spellingherziening, de grote spellingherziening