Highlights provide a way of coloring certain bytes in a file for identification. For example, with highlights all of the bytes with values 128 to 255 could be colored to identify non-ASCII bytes. The Highlight Options dialog can be accessed by clicking the 'Tools > Options...' menu option and selecting Highlights from the list, or clicking 'View > Highlight > Edit Highlights...'. Highlights can be turned on or off by clicking on them in the 'View > Highlight' menu. The enabled highlights are associated with an Editor Interface (see Working with Interfaces for more information).

All available highlights are displayed in a list at the top of the dialog. Click New to generate a new highlight, or select an item in the list and click Delete to remove the highlight. Clicking the up or down arrows will change the selected item's position in the list.

When a highlight is selected from the list, its details will be displayed in the Highlight Options box. The name entered in the Name field will appear on any menu where the highlight will be accessed. If the Visible toggle is turned off, the highlight rule will not appear on any menus. The Ranges field contains which byte values will be highlighted by this rule. Enter a byte value in any of the available numeric formats (see Introduction to Number Systems). Multiple byte values can be separated by the ',' character, or a range of bytes can be specified using '..'. For example, '0..31,127' will highlight bytes 0 to 31 inclusive, and 127.

The bytes in the current file that match this highlight rule will be colored. If the Use Default Highlight Color toggle is enabled, the bytes are colored according to the Highlighting color in the Color Options dialog. If the Custom Color toggle is enabled, the bytes are colored according to the Fore and Back color boxes. Using custom colors, multiple highlights can be turned on at the same time using different colors.

The following Highlight rules are available by default:

• Linefeed Characters - 0x0d and 0x0a

• Alphanumeric Characters - all letters and numbers

• Control Characters - any of the bytes from 0 to 31

• Non-ASCII Characters - any of the bytes from 128 to 255

Click the Reset button to restore all Highlight rules to their original values.