Domains Screen
The Domains screen contains general attributes that are common to all domains. The Type you enter on this screen for a domain governs the subsequent screens that APPX displays to further define the domain. Domain specifications establish values for all fields that reference the domain and cannot be overridden. Therefore, it may be desirable to leave some attributes blank (such as descriptive name or column headings) to allow for making individual entries at the field level.
You access the Domains screen, shown in Figure 2-3-1, by selecting domains from the Database Management menu overlay.
Figure 2-3-1. Domains Screen
The Domains screen contains the following fields:
· Domain Name uniquely identifies the domain within an APPX application. Fields assume the attributes of a domain by referencing the domain’s Domain Name. (22 uppercase alphanumeric characters, restricted to numbers, letters, and spaces).
The name may represent a specific field that references the domain, such as an Account Number domain, or a category of fields, such as an Amount domain that is referenced by a number of different fields, including AP Invoice Amount, Sales, AR Invoice Amount, Total Purchases, and Order Amount.
· Type categorizes the domain according to its specific content or function in APPX. The specifications presented on subsequent screen overlays depend on the Type entered here, although most types share some common specifications. The domain Type options are:
Alpha, for field patterns that can contain numbers, letters, and special characters (such as -, #, or &).
Format, for field patterns where edit mask is the primary characteristic.
System, for field patterns that contain data provided by the system, often referred to as audit fields.
Text, for field patterns comprised of blocks of text.
Token, for field patterns with specific values that are stored as corresponding numbers.
Numeric, for field patterns restricted to number, decimal (.), and sign (-) entries.
Date, for field patterns that contain dates and/or times, from a hundredth of a second through a century.
Logic, for field patterns
with possible values of yes 
or no 
, or 
to represent an unknown value.
Same As, for field patterns that share the same characteristics as a domain in another application in your database.
If you enter a partial value, APPX selects the option with the next highest value. For example, an entry of ALPHA or A is equivalent to entering ALPHA. An entry of C references the next highest value: DATE. Each option is discussed in detail in the corresponding section.
· Format displays a symbolic representation of the domain for ease of reference. It is generated by APPX according to the detail specifications entered for the domain and cannot be edited.
· Options are indicators that display whenever documentation (T), data lookup (DL), or additional attributes (AA) have been defined for this domain.
Three options are available from the Domains screen as described in the corresponding sections:
· Toolbox