Meaning
What does NOMAP mean?
NOMAP is an acronym for “Non-Offending Minor Attracted Person”, in other words, a pedophile who is open about their attraction to children.
The short version is just MAP, meaning Minor Attracted Person.
By creating the term and being open about their socially unacceptable sexuality, NOMAPs aim to get accepted as a part of the LGBTQ community, however, they refuse to claim them.
NOMAPs are people who are attracted to children, but has not assaulted a child nor watched any content. They want to be viewed as other people and gain sympathy for their sexual orientation.
Naturally most people are disgusted by the thought of someone being sexually interested in children.
Origin
What's the origin of NOMAP?
The slang is rather new, only created in the end of the 2010’s.
Exactly who coined it is not clear, likely because the person received major backlash for their orientation, and decided to stay anonymous.
Spread & Usage
How did NOMAP spread?
There was a major outrage in 2018 that the LGBTQ community was ready to take in NOMAPs, however, this turned out to be a hoax to create hostility against LGBTQ as a whole.
The majority of people despise NOMAPs, as they claim that sexual attraction to children is nothing to take pride in, while others support them and view it as a mental illness, as long as the NOMAP does not actually harm any children.

External resources
-
Heavy.com – How Pedophiles Silently Took Over Social Media