There will be no central register of everybody who lives in HoloWorld. A person is perfectly free to go off and live in a hut in the woods and not be recorded anywhere.
There won't either be centralized mandatory registers of different types of people, like people who drive cars, people who go to school, etc.
However, any more local organization is free to demand that it knows the people in deals with, and that people provide references to other organizations that know them.
In other words, you're welcome to go and hide away and keep all information about yourself private, but you can not demand that specific businesses or communities must admit you into their midst or do business with you, if they don't know you.
Relationships are key. There is no enforced relationship with a central government that has thick files on you. But if you want something from somebody under conditions that carry any kind of risk to them, you would need to be prepared to establish some kind of relationship of trust with them first. If you're going to rent a car from somebody, or you're going to live in their house, they might feel better about it if you can show them a history of your prior life, and an indication that other people have been happy with you.
Registers of other people are fine. However, they are not to be monopolized, and they are primarily reactive rather than proactive. Nobody has a right to go and track down all people of a certain kind (plumbers, tax-payers, etc.) and force them to be in a register, or force them to behave in a certain way. But an organization is free to make a register of plumbers they've run into that they were happy with and those they weren't happy with. And they are also free to let others access that information.
Trust relationships and the appreciation of other people will naturally become valued commodities. Therefore you will find that many people will voluntarily choose to have themselves recorded in various registers where others can then look up their profile and history and relationships. Essentially, the more people are on record as knowing you, trusting you and appreciating you, the faster you might enter into a useful relationship with a new person you haven't met before, the more places you will have easy access to. This is of course not to discount the value of personal intuition, and being able to perceive in the moment who you can trust and who you can't.
Since there is no centralized register of everybody, and no centralized way of identifying people, there is always the option of dropping out of the system one is in and becoming anonymous. It will rarely be an advantage, but the option is there. You can always go somewhere else. You can always move somewhere where they don't care who you are and start over again.
Of course, in many places, if one insists on being totally anonymous or having no history of any kind and no trust relationships one can point to, one might well be considered some kind of criminal. And with good reason, as the most likely reason for wanting to become anonymous is either that one currently has something discreditable to hide, or that one has messed up one's life so badly that one feels it is best to start over again.
Communities or families are quite likely to establish means of identification amongst themselves. For example, there is nothing to stop a certain family from all having electronic devices implanted under their skin, so that they could always know where eachother are, and thereby feel more secure. Likewise, a gated residential community might well demand that anybody who enters is fingerprinted or DNA tested or something, so that they can identify different classes of visitors and so that there is a record of people if they turn out to act criminally or something like that. However, any schemes like that can only be local and voluntary. Local communities can always enact rules or schemes that limit privacy within their boundaries, but it has to be very clear what is going on, and there is completely free choice about whether one wants to enter that community or not, and whether one wants to leave it if one is there.
So, you have an inherent right to privacy, meaning that you can withdraw or hide from society and be or do whatever you feel like within the boundaries of your privacy. You have no right to enforce your privacy on others who don't want to deal with you as a private or anonymous person.
Don't get the idea that HoloWorld is a very compartmentalized society. OK, those who choose to drop out and hide from everybody else, can. But the vast majority will choose to be connected up with others in a great many ways, and to explore the diversity of humankind and of life by interacting with many different people and environments. Most people will choose to know and to be known, and as such privacy is of little concern. However, it is there when somebody wants it, either partially or in whole.
Most people will have parts of their lives and information about themselves that they will freely share with the world, and parts which they keep private. In the electronic world, that is becoming increasingly easy to do. You can tell people extensively about yourself, without them having to know where you live. You can show one side of yourself and leave another side hidden. What to keep private and what to make public is the choice of the individual.