176 IBM Content Manager OnDemand Guide
Machine carriage controls
Machine carriage controls are in data that is created on z/OS.
Because machine carriage controls are binary values, if a file contains them, it must always 
be transferred as binary. Machine carriage controls cannot be converted to ASCII. For a list of 
machine carriage control values, see the following website: 
http://ibm.co/1M2ZtSG
AFP Structured Fields
AFP , which is also called Mixed Object Document Content Architecture (MODCA), is a 
printing architecture that was designed and created by IBM. The beginning of each AFP 
record is called the AFP Structured Field Introducer. The following sample shows an example 
and description of an AFP Structured Field Introducer (which is shown in the hexadecimal):
5A 00 10 D3 A8 A8 00 00 00
/SM590000The first byte is always x'5A'.
/SM590000The second and third bytes are the length (maximum length of 32767).
/SM590000The fourth byte is always x'D3'.
/SM590000The fourth, fifth, and sixth bytes are the Structured Field Identifier, for example, x'D3A8A8' 
or x'D3A8AF'.
/SM590000The seventh byte is the flag byte. The last two bytes are reserved and usually zeros.
/SM590000The information that follows the reserved bytes depends on the Structured Field.
/SM590000The length does not include the x'5A'.
For more information, see the Mixed Object Document Content Architecture (MO:DCA) 
Reference, AFPC-0004-08, at the following website:
http://afpcinc.org/afp-publications/
The following two examples in hexadecimal of the AFP Structured Field Introducer show the 
most common Structured Fields that you might see at the beginning of an AFP file:
5A 00 10 D3 A8 A8 00 00 00       Begin Document (BDT)
5A 00 5B D3 A8 C6 00 00 00      Begin Resource Group (BRG)
An AFP Structured Field can begin with the 2-byte length prefix (which is called record 
format):
00 11 5A 00 10 D3 A8 A8 00 00 00
The length in the 2-byte prefix is one greater than the length in the Structured Field because 
the 2-byte prefix includes the x'5A', but it does not include itself.
When you work with ACIF , it is important to know the format of the data. Use the arsafpd 
utility or look at the input in a hex editor to be sure.