in the Planet odf
 

what does the "requiresTerraform" line modify?

Absolutely nothing!
 

Originally, the line was intended as a requirement for colonization (if you can't terraform the planet, you couldn't colonize it). Activision apparently changed this b/c you don't need to terraform a Class M planet to colonize it.

Therefore, that line is useless. However, that doesn't mean you need to delete it. A value of 1 or 0 will make little or no difference.

That sounds like a good idea, wonder why they got rid of it.