How to block a specific fact coming to foreman

How to block a specific fact coming to foreman.

Facter version is : 1.7.5

I could see in Facter 3.6 version we have a blocklist group where we can
add facts to block in facter.conf, but i dont know in facter 1.7.5 where or
how we can block a fact.

Can some one suggest or guide me on this.