The name of a SEA has a dot (.) as a prefix. This identifies the extended attribute as a SEA.

The values of Standard Extended Attributes can be multi- or single-valued, with formats following the data type conventions discussed previously.

Where entries for Standard EAs consist of ASCII characters, case is important.

The Standard EAs that have been defined are:

Any extended attribute that is defined by the system starts with a period. This allows our software vendors to freely define new extended attributes without conflicting with ours, as long as they follow the convention that non-system extended attributes don't start with a period.

The .TYPE and .ASSOCTABLE extended attributes (EA) are two of the most useful SEAs.

The .TYPE extended attribute indicates what type of data is in a file. It also implies what programs can edit the file, and what icon is to be used for the file. OS/2 can use the .TYPE EA to determine a default application to run and a default icon for a file of a particular type (if there is a .ICON EA, it will be used instead of the icon associated with a particular data type).

The .ASSOCTABLE extended attribute allows an application to indicate the type, extension, and icon for data files that it recognizes. It also contains an ownership flag. This data can be automatically installed by OS/2. When your program recognizes files created by other programs, you might want to install .ASSOCTABLE EA entries for those other programs.

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