Extended Attribute Data Types

The first WORD of an EA specifies the type of the EA. The following EA types are defined (see Maintaining Multi-Value EAs in REXX for example REXX code to handle EAs): 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_ASCII      │'FFFD'x        │
└───────────────┴───────────────┘
Description:
This EA contains ASCII text. The first WORD following the data type specifies the length of the data; the next bytes are the data.
Example: EAT_ASCII '0005'x 'Hello' 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_BINARY     │'FFFE'x        │
└───────────────┴───────────────┘
Description:
This EA contains binary (non-text) data. The first WORD following the data type specifies the length of the data; the next bytes are the data.
Example: EAT_BINARY '0003'x '01'x '02'x '03'x 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_BITMAP     │'FFFB'x        │
└───────────────┴───────────────┘
Description:
This EA contains bit map data. The first WORD following the data type specifies the length of the data; the next bytes are the data.
Example: EAT_BITMAP '0203'x bitmap_data 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_METAFILE   │'FFFA'x        │
└───────────────┴───────────────┘
Description:
This EA contains metafile data. The first WORD following the data type specifies the length of the data; the next bytes are the data.
Example: EAT_METAFILE '0203'x metaFile_data 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_ICON       │'FFF9'x        │
└───────────────┴───────────────┘
Description:
This EA contains icon data. The first WORD following the data type specifies the length of the data; the next bytes are the data.
Example: EAT_ICON '1BF8'x icon_data 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_EA         │'FFEE'x        │
└───────────────┴───────────────┘
Description:
This EA contains the ASCII name of another EA that is associated with the file. The contents of that EA are to be included in the current EA. The first WORD following the data type specifies the length of the name of the other EA; the next bytes are the name of the EA to include.
Example: EAT_EA '0008'x AB.STUFF 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_MVMT       │'FFDF'x        │
└───────────────┴───────────────┘
Description:
This EA contains multi-valued, multi-typed data -- two or more consecutive extended attribute values. Each value has an explicitly specified type.
The first WORD following the data type specifies the codepage (0000 means default); the second WORD following the data type specifies the number of the following entries. The next bytes specify the EA values in the "normal" EA format (see the description for the other entries). Note that the Code page data is for use by the application; the operating system does not use it.
Example: EA_MVMT '0000'x '0003'x EAT_ASCII '0005'x Hello
EAT_EA '0008'x AB.STUFF
EAT_BINARY '0003'x '01'x '02'x '03'x 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_MVST       │'FFDE'x        │
└───────────────┴───────────────┘
Description:
This EA contains multi-valued, single-typed data-two or more consecutive extended attribute values. All values have the same type.
The first WORD following the data type specifies the codepage (0000 means default); the second WORD following the data type specifies the number of the following entries. The next word specifies the data type of the values and after that the data of the values follow.
Example: EAT_MVST 0000 0003 EAT_ASCII 0004 Mark
0005 Ellen
0003 Liz 

┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│EAT_ASN1       │'FFDD'x        │
└───────────────┴───────────────┘
Description:
This EA contains ANS.1 field data; an ISO standard for describing multivalue data streams. 
┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│               │'8000'x and up │
└───────────────┴───────────────┘
Description:
These values are reserved for the Operating System. 
┌───────────────┬───────────────┐
│Data Type      │Value          │
├───────────────┼───────────────┤
│               │'0000'x -      │
│               │'7FFF'x        │
└───────────────┴───────────────┘
Description:
These values can be defined by the user. All user-defined data types should be length-preceded, meaning that a WORD indicating the length of the data (in bytes) precedes the data.

Source: Control Program Guide and Reference