doc, man: Clarify that R³ values are case sensitive

This is clear from the deb822(5) man page, but we can make this more
clear on the brief format description for each of these file formats.

Prompted-by: Niels Thykier <niels@thykier.net>

doc/rootless-builds.txt

@@ -25,7 +25,7 @@ We add a new field to the "Source" stanza of debian/control:
 
   Rules-Requires-Root: no | binary-targets | <implementations-keywords>
 
-The values are defined as:
+The case sensitive values are defined as:
 
  * If "no", then "debian/rules binary" will not require root at all (not even
    fakeroot).

man/deb-buildinfo.pod

@@ -35,7 +35,8 @@ Each field begins with a tag, such as
 B<Source>
 or
 B<Binary>
-(case insensitive), followed by a colon, and the body of the field.
+(case insensitive), followed by a colon, and the body of the field
+(case sensitive unless stated otherwise).
 Fields are delimited only by field tags.
 In other words, field text may be multiple lines in length, but the
 installation tools will generally join lines when processing the body

man/deb-changes.pod

@@ -35,7 +35,8 @@ Each field begins with a tag, such as
 B<Source>
 or
 B<Binary>
-(case insensitive), followed by a colon, and the body of the field.
+(case insensitive), followed by a colon, and the body of the field
+(case sensitive unless stated otherwise).
 Fields are delimited only by field tags.
 In other words, field text may be multiple lines in length, but the
 installation tools will generally join lines when processing the body

man/deb-control.pod

@@ -40,7 +40,8 @@ Each field begins with a tag, such as
 B<Package>
 or
 B<Version>
-(case insensitive), followed by a colon, and the body of the field.
+(case insensitive), followed by a colon, and the body of the field
+(case sensitive unless stated otherwise).
 Fields are delimited only by field tags. In other words, field text
 may be multiple lines in length, but the installation tools will
 generally join lines when processing the body of the field (except

man/deb-src-control.pod

@@ -41,7 +41,8 @@ least one field. A field starts with a fieldname, such as
 B<Package>
 or
 B<Section>
-(case insensitive), followed by a colon, the body of the field and a newline.
+(case insensitive), followed by a colon, the body of the field
+(case sensitive unless stated otherwise) and a newline.
 Multi-line fields are also allowed, but each supplementary line, without a
 fieldname, should start with at least one space. The content of the multi-line
 fields is generally joined to a single line by the tools (except in the case of

man/dsc.pod

@@ -34,7 +34,8 @@ Each field begins with a tag, such as
 B<Source>
 or
 B<Binary>
-(case insensitive), followed by a colon, and the body of the field.
+(case insensitive), followed by a colon, and the body of the field
+(case sensitive unless stated otherwise).
 Fields are delimited only by field tags.
 In other words, field text may be multiple lines in length, but the
 installation tools will generally join lines when processing the body