CMNT Chunk

See more on Chunks in general.

This is a “Comment”, used to annotate files stored in the archive. Both text and icon annotations are provided.

CMNT Chunk structure


a (correlated) Set.
b (subtype) Set.
r (range of instances) all used in the general manner.
p (multi-part) & c
y (payload specification)
i (instance sizes) Set when r is set, Clear otherwise.

The y flag may be present, as you may want to compress the text comments, and if the file content is encryped you may want to encrypt this comment too.

CMNT-nd has a distinct meaning, documented below.


The Subtype indicates different kinds of annotations for the file.

annotation subtypes

Instance Number

The Instance Number matches the Instance Number of the DATA it applies to, as with any a-flagged chunk type.

CMNT Chunk Payload

The Payload contains information that is displayed to the user when browsing an archive, but is not considered part of the file and is not restored as an attribute of that file during extraction.

A Text comment is an lpstring.

An Icon is a uintV containing the Instance Number of an ICON chunk.

Usage Notes


CMNT-nd Chunk

CMNT-nd indicates that the specified instances are in a different file in a multi-part archive.

This works the same as with DATA-nd chunks.

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