Question

what
are the rules used to write a field name in MS Access

Answer 1

1- Create tables with meaningful names. For example, if you want to create a table that stored information about your suppliers, then name the table Suppliers.
2- Even though Access allows spaces in your table names, you may want to consider using the underscore character ("_") instead of a space. This will make it easier for you in the long run if you decide to port your tables to a different database. Most other databases do not allow spaces in table names.

For example, if you wanted to create a table that stored your order details, instead of calling the table Order Details, you might want to consider naming the table Order_Details.