User story:

As a Business Analyst / Developer, I can define validation for fields in my content type. For example: required, accepted sizes, predefined values, regex, ranges, and types.

Defined in the actual content type definition - validation is not a presentation detail.

Acceptance criteria:

• A developer can define validation rules on a field in the content type definition.
• Multiple validation criteria allowed per field.
• When validation is not passed, the editor does not allow saving the content.
• Helpful validation messages are displayed in editing UI.
• Proper HTML5 input types are used in the editing UI where applicable to provide useful input masks - ie email, url, tel, number, range, date, month, week, time, datetime, color
• https://wiki.magnolia-cms.com/display/TH2/Content+Types+Stories#ContentTypesStories-Criteria