Trusted Extensions Label Administration

Specifying Channels

The CHANNELS section in the label_encodings file defines the lines that can appear below the PRINTER BANNERS lines on the lower third of the banner and trailer pages. The CHANNELS section can be specified to print a string whenever the label of a print job contains a certain compartment.

Commercial sites can customize the text in the CHANNELS section with any compartment bit. The following figure shows a CHANNELS warning on a print job's banner page at a commercial site.

Figure 17  Commercial Use of CHANNELS Section on Banner Page

By convention in U.S. government installations, the channels lines of the banner page show the warnings that are associated with the compartments of the print job's label. U.S. Government Use of CHANNELS Section on Banner Page shows a typical CHANNELS warning on a print job's banner page at a government installation: HANDLE VIA (CH B)/(CH A) CHANNELS JOINTLY.

The following discussion shows how the CHANNELS string HANDLE VIA (CH B)/(CH A) CHANNELS JOINTLY is specified for a print job whose label includes the compartment words A and B. For the purpose of the example, only (CH A) and (CH B) apply. However, because the compartment bit for a third channel (CH C) is included in the definitions, (CH C) is also mentioned in this discussion.

The example illustrates these features:

• Two compartment bits are associated individually with one set of words and together with another set of words.

• A third compartment bit is included with the encodings for the first two bits.

• One suffix is defined for when any combination of one or more channel words is in the label.

• Another suffix is defined for when a single channel word is in the label.

• A third suffix is defined for when more than one channel word is in the print job's label.

Figure 18  U.S. Government Use of CHANNELS Section on Banner Page

In the following example, two suffixes CHANNELS JOINTLY and CHANNELS ONLY and a prefix HANDLE VIA are defined.

Example 12  Suffixes and Prefixes in the CHANNELS Section in a U.S. Government label_encodings File

CHANNELS:

WORDS:
name= CHANNELS JOINTLY;         suffix;
name= CHANNELS ONLY;            suffix;
name= HANDLE VIA;               prefix;

Next, the channel names (CH A), (CH B), and (CH C) are specified in two different ways to achieve the following results:

• When any one of the three compartment bits that is associated with channels is in the label, the HANDLE VIA: prefix is printed.

• When only one of the three compartment bits that is associated with channels is in the label, the CHANNELS ONLY suffix is printed after the channel name (CH A), (CH B), or (CH C).

• When more than one compartment bit that is associated with channels is in the label, the prefix is followed by each channel name separated by a slash (/). This channel name is then followed by the CHANNELS JOINTLY suffix.

In the following example, the first three lines that define CHANNELS words in the preceding example are repeated.

This example focuses on how (CH A), (CH B), and (CH C) are encoded to appear with the CHANNELS ONLY suffix.

• (CH A) is encoded with bit 0 turned on and bits 1 and 6 explicitly turned off using the tilde (~): 0 ~1 ~6

• (CH B) is encoded with bit 1 turned on and bits 0 and 6 explicitly turned off using the tilde (~): ~0 1 ~6

• (CH C) is encoded with bit 6 turned on and bits 0 and 1 explicitly turned off using the tilde (~): ~0 ~1 6

CHANNELS:

WORDS:

name= CHANNELS JOINTLY;         suffix;
name= CHANNELS ONLY;            suffix;
name= HANDLE VIA;               prefix;
name= (CH A);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= 0 ~1 ~6;
name= (CH B);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= ~0 1 ~6;
name= (CH C);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= ~0 ~1 6;

The first three lines of name definitions in the CHANNELS section have the following results:

• The HANDLE VIA prefix and the CHANNELS ONLY suffix are printed when one of the words that is associated with bits 0, 1, and 6 elsewhere in the label_encodings file is in the print job's label

• The HANDLE VIA prefix and CHANNELS ONLY suffix are printed:

  • With (CH A) when compartment bit 0 is turned on in the label, and compartment bits 1 and 6 are turned off

  • With (CH B) when compartment bit 1 is turned on in the label, and compartment bits 0 and 6 are turned off

  • With (CH C) when compartment bit 6 is turned on in the label, and compartment bits 0 and 1 are turned off

The last three lines in the preceding example are repeated in the following example. The repetition shows how (CH A), (CH B), and (CH C) are encoded to appear with the CHANNELS JOINTLY suffix when more than one of the words that is associated with bits 0, 1, and 6 is in the print job's label. A slash is inserted between the channels names when more than one of the bits that is defined in the CHANNELS section is in the print job's label.

Example 13  Encodings for More Than One Channel in CHANNELS Section in a U.S. Government Encodings File

name= (CH A);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= 0 ~1 ~6;
name= (CH B);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= ~0 1 ~6;
name= (CH C);   prefix= HANDLE VIA; suffix= CHANNELS ONLY; compartments= ~0 ~1 6;

name= (CH C);   prefix= HANDLE VIA; suffix= CHANNELS JOINTLY; compartments= 6;
name= (CH B);   prefix= HANDLE VIA; suffix= CHANNELS JOINTLY; compartments= 1;
name= (CH A);   prefix= HANDLE VIA; suffix= CHANNELS JOINTLY; compartments= 0;

These CHANNELS definitions illustrate the importance of order when compartments are being encoded. The first three lines handle the cases when only one of the channels' compartment bits is turned on, so the last three lines can handle cases when more than one bit is turned on. Therefore, none of the last three lines need to have any compartment bits explicitly set to 0. The result of these last three lines is that the suffix CHANNELS JOINTLY is always printed when any of two or more of the three compartment words that are associated with the channels is in the label.

• (CH C) is printed with CHANNELS JOINTLY when bit 6 is turned on, and either of bit 0 or 1, or both, are also turned on.

• (CH B) is printed with CHANNELS JOINTLY when bit 1 is turned on, and either of bit 0 or 6, or both, are also turned on.

• (CH A) is printed with CHANNELS JOINTLY when bit 0 is turned on, and either of bit 6 or 1, or both, are also turned on.

The following excerpt from the label_encodings file shows that compartment bit 6 is associated with the label word CC.

SENSITIVITY LABELS:


WORDS:
.
.
.
name= CC;                       minclass= TS; compartments= 6;

The next excerpt shows that compartment bit 1 is associated with the sensitivity label word B.

SENSITIVITY LABELS:

WORDS:
.  .  .
name= B;                        minclass=  C; compartments= 1;

The next excerpt shows that compartment bit 0 is associated with sensitivity label word A.

SENSITIVITY LABELS:

WORDS:
.   .   .
name= A;                        minclass=  C; compartments= 0;

To summarize, the channels line prints as HANDLE VIA (CH B)/(CH A) CHANNELS JOINTLY because of the following specifications:

• HANDLE VIA is defined to always appear with any CHANNELS word.

• The sensitivity label has two access-related words, A and B, that are associated with two compartment bits, 0 and 1.

• Because two of the bits that are defined for CHANNELS words appear in the print job's label, the CHANNELS WORDS (CH A) and (CH B) are followed by CHANNELS JOINTLY.

  Any string that must print before the channel name is specified as a prefix. Any string that must print after the channel name is specified as a suffix.

For a sample CHANNELS planner, see Planning the Channels in a Worksheet.