Creating new fields in the "Events" table.

Hello and happy new year to everyone !!
I would like to ask how I can safely add new custom fields in my Events table (the equivalent of your ZuluSampleEvents table). I think I can add new fields after the Publish button(and process) has been done but I want to make sure for the future.
If I correctly understood, I have to use a prefix for the name of my custom field (i.e.: "X-"). So, my custom field would be "X-ProjectPhaseId_NK". I guess the Publishing process won't look these prefixed fields. Am I correct ?
I would like to ask how I can safely add new custom fields in my Events table (the equivalent of your ZuluSampleEvents table). I think I can add new fields after the Publish button(and process) has been done but I want to make sure for the future.
If I correctly understood, I have to use a prefix for the name of my custom field (i.e.: "X-"). So, my custom field would be "X-ProjectPhaseId_NK". I guess the Publishing process won't look these prefixed fields. Am I correct ?