Document conventions

literal

In syntax sections, non-italic text is literal; this does not apply to white space and the symbols [ ] { } | *.

'literal'

In descriptive sections, non-italic text in single quotes is literal.

parameter

Italics indicate a variable or parameter, to be substituted with an actual value.

command=

A name with a trailing '=' refers to an Image Serving HTTP Protocol command.

attribute::Item

A name prefixed with attribute:: refers to an image catalog attribute.

catalog::Item

A name prefixed with catalog:: refers to an image catalog data field.

icc::Item

A name prefixed with icc:: refers to a field in the ICC color profile map.

font::Item

A name prefixed with font:: refers to a field in the font map.

macro:: Item

A name prefixed with macro:: refers to a field in the macro definition table.

ruleset::Item

A name prefixed with ruleset:: refers to an element in a URL pre-processing rule set.

default::Item

A name prefixed with default:: refers to an attribute of the default image catalog.

[ optional ]

Optional syntax elements are enclosed by square brackets.

*[ optional ]

The optional syntax element may be repeated none or more times.

item1 | item2

A vertical bar indicates that either the single syntax item to the left or the item to right may be used. Exactly one item must be selected.

{ group }

Curly braces are used to group syntax elements.

*{ group }

The syntax elements within the group may be repeated one or more times.

white space

White space (spaces or tabs) is not allowed in HTTP requests. This document occasionally uses white space between syntactic elements for clarity only.