How to add new calculation type?

[gotwals]

I wish to add "Natural Transition Orbitals" to my Gaussian16 list of calculation types. Which file(s) need to be modified?

[schmidt]

Note that NTOs are automatically parsed and can be visualized in WebMO 22 and higher. WebMO 22+ also contains a job template (for Gaussian and QChem) to calculate and output these orbitals.

For earlier versions, it would be easy to add a new job "template" to calculate the transition orbitals, but the parsing would be tricky and the visualization impossible.