A lot of adjacent discussions in "Coin Collecting". However, you are doing something more generic: setting up a data base of objects. Having done that before, here is some experience:

You have only two problems: "will the numbers be descriptive or sequential" and "how do I connect the numbers to the objects". Excel or a data base programme will do everything else.

Sequential numbers have little or no information. An example is UK license plate numbers. Dutch license plate numbers have some information, as their format and numerical or alphabetical order betrays the age of the car. EU bank account numbers carry a lot of information: bank, bank branch, account number (the only sequential part) and checksum. The more information a number carries, the more numbers cannot be used. For instance, a number that uses time cannot have a higher value than 24 for the first two digits and 60 for the second pair, a huge waste of possible numbers. Logically, sequential numbers (6 for Dutch license plates) are shorter than descriptive numbers (23 for EU bank account numbers, counting only the IBAN part).

The most obvious descriptive numbers for a coin data base are catalogue numbers. For modern coins, taking the example of KM, they would take 5 fields: catalogue name, country name, catalogue number prefix, catalogue number, catalogue number suffix. This would give you sortable fields, so your data base can be sorted back to the correct order, and unique numbers for a type collection. For a date collection, you need a dating system (AD, AH, Saka etc.) and date field. Only at this point can you enter descriptions.

The most obvious sequential set starts with 1 and can be prolonged to infinity (don't use leading zeroes or you must put them in by hand in Excel and many data base systems.) Excel et al. can generate such a number set automatically. The numbers contain no information other than the order in which you entered them into your data base. Your descriptions survive by the grace of your ability to link coin with data base (inventory) number.

Doing that it is a big bad problem if your coins are stored loose. Putting a piece of paper in a coin cabinet is not a good idea: the paper will attack metal. One system I can think of is numbering the drawers and having a "map" of each of the drawers in your computers. Another would be to add the location of the coin in your data base, e.g 3.2.1.1 would be cabinet 3, drawer 2, first "row" first "column". Both systems are awkward to painful when you acquire a new coin that you want somewhere in between which means that something like 30 to 60 coins need to move one place to the right. Also, unless you want to move masses of coins to insert one, you will get drawers with one or two coins; a massive waste of space.

If your coins are in cartons, the pain decreases very considerably: you can put your inventory number on the carton and be done with it. However, there are people who do not wish to use cartons.

Peter