Requirements Expected Input/Ouput and Validation

Requirement - Expected data

When you create a requirement it will be nice to have default options like

Data Input
Data output
Data Validation

For example, if it is a Credit Card Registration requirement:

Description:

As a user of the platform, I would like to register my credit card for future purchases.

Data Input:

+ Credit Card # 
+ Expiration Date 
+ CVV 
+ Owner Name

Data Output:

+ API code 200 OK 
+ The platform will render an appropriate dialog as a response for the user, any value other than 200 is considered a failure.

Validation:

+ Validate length for each value entered 
+ Check CC # with Luhn algorithm

We used the + comments to accomplish this goal, however, I think it will be nice to have something like this.

I think it will be useful in a Trello card, so the developer knows which data he has to consider when coding that logic.

Regards