I was actually customizing a registration form of my website, I needed to add an extra field for date of birth which I did using this joomla_docs
Now I need to validate this field , I read this doc
but I couldn't understand how this custom validation part works , is there only one validate.js? . Where do I exactly add the code? It says after loading validate (What does it exactly mean?).
If I do anything with that validate.js itself , would it be a core code modification? (I found validate.js at system/js.validate.js but it's a minified file)