insertion
noun
uk/ɪnˈsɜːʃən/ us [ U ]
the act of putting one thing into something else, or of adding something to something else:
The company has encouraged the insertion of exclusion clauses in contracts to prevent executives going over to the competition.
[ C ] MARKETING
an insert noun :
Please ask for our rates for colour insertions into our magazines.
[ C ]
something that you add to something else:
editorial insertions