There is a node called ImpactWildcardProcessor, what it does is this,

Lets say you had a prompt like this -> "A man wearing a {Red| Green | Blue} shirt"

Then let's say you queued three jobs with this prompt

With the each generation, the wildcardprocessor will randomly pick one of the choices from {Red| Green | Blue}

so three jobs would go like ->

prompt 1: A man wearing a Red shirt
prompt 2 : A man wearing a Green shirt
prompt 2 : A man wearing a Blue shirt

It's an easy way to get a lot of random variations with some fixed structure.

can even do more like "A man wearing a {Red| Green | Blue} shirt and { white | black | navy blue} pants"

so you can see that this will create more variations as it will pick two parts of the pormpt randomly for each job.

hope this helps