ARM documentation for no-case-compress ACL seems inconsistent
<para>
Specifies a list of addresses which require responses
to use case-insensitive compression. This ACL can be
used when <command>named</command> needs to work with
clients that do not comply with the requirement in RFC
1034 to use case-insensitive name comparisons when
checking for matching domain names.
</para>
<para>
If left undefined, the ACL defaults to
<command>none</command>: case-insensitive compression
will be used for all clients. If the ACL is defined and
matches a client, then case will be ignored when
compressing domain names in DNS responses sent to that
client.
</para>
The first paragraph says that it "Specifies a list of addresses which require responses to use case-insensitive compression." while the second paragraph says the opposite, that when the ACL has a value of "none" (meaning that no addresses match) that "case-insensitive compression will be used for all clients."
Based on a code analysis by @pspacek, I believe that the extent of the inconsistency may be the phrase "If left undefined, the ACL defaults to none
: case-insensitive compression will be used for all clients.", which seems like it should read instead "If left undefined, the ACL defaults to none
: case-sensitive compression will be used for all clients."
Testing is recommended to validate behavior before making changes.