De or het indexmarkering?

The correct Dutch article is:

de indexmarkering

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

How to use indexmarkering

the indexmarkeringde indexmarkering
this indexmarkeringdeze indexmarkering
that indexmarkeringdie indexmarkering
our indexmarkeringonze indexmarkering
your indexmarkeringjouw indexmarkering
every indexmarkeringelke indexmarkering
which indexmarkering?welke indexmarkering?
a big indexmarkering / the big indexmarkeringeen grote indexmarkering, de grote indexmarkering