006 Validation-Functions
https://angular.io/api/forms/Validators

009 Form-Controller-Status
https://angular.io/api/forms/AbstractControl

013 Email-Validator
https://angular.io/api/forms/Validators#email

014 Validators-Min
https://angular.io/api/forms/Validators#min

015 Pattern-Validator
https://angular.io/api/forms/Validators#pattern

015 Regular-Expressions-Tool
https://regexr.com/

016 NGX-Mask
https://www.npmjs.com/package/ngx-mask

018 FormGroup-Class
https://angular.io/api/forms/FormGroup

018 Tailwind-States
https://tailwindcss.com/docs/hover-focus-and-other-states