Questions about ID in the registrations of a web rearguard system

The key point of your question is this:

  

"[...] all the registrations have the registration (ID or Code) and they   are very important for customers to use to relate a   register with the other [...] "

Yes, they are certainly important ... to the company that created and uses the system . First of all, it is a nuisance for a user to have to remember a code, however short it may be. Second, in terms of identification data, nothing is more important to the customer than their own name. Certainly the clients of these registrations you mention would prefer to use their names to relate. Do not believe? Ask the customers. Or do an empathy exercise and put yourself in their shoes with some service you use (telephony, entertainment, etc.).

If the code is something really necessary to the business, ease the life of the customer by putting it on a card. This is not a brilliant idea: filmmakers have been doing this for a long time (in the days when they still persisted). If you need a code, let the customer define it. This is called a login, and email is usually used not only by the contact, but by the uniqueness.

Well, now considering the user not the client, but the person who deals with the client and uses this interface for some relationship, the code is even less necessary. What this user really needs to know is the name of the customer, perhaps your email and other data of the user's identity or their situation in the business, depending on the problem's domain. In fact, in a well-done system, the lines in this table already demonstrate the action that the user needs to take in relation to that customer, and if they do not even make the phone call (an example of telemarketing) even while displaying the phone. Why would the ID be needed in addition to its use in the database tables, ie why would it be necessary in the interaction?

You need to answer the question, like every UX issue.

Do you need to show this ID for some reason? Does the user need to be aware of this? Maybe to get some support? Can you optionally display?

I would not put anything that is not very necessary. And even if for secondary reasons I would create an optional way to show information, I do not know, an advanced mode or support.

It would be different if this is a client code or something. Even in this case I'm not a fan of the idea. I prefer to make the user more comfortable by configuring information that is part of his domain.

Do not show does not mean that it is not present in the whole system.

I find the statement in the last sentence a bit strange, but if this is true it may be a reason to use this code. But this code coming from something external does not seem to be a primary key, at least it should not be. There the ID still becomes necessary and has one more reason for it not to be shown. But the natural code would be. Do not confuse database ID (substitute key) with natural key that the user understands.

See more at Surrogate Key and Natural Key .