function is defined inside a code block

Prolint rule "nestedfunc" warns when it finds a function definition (or a procedure definition) inside a code block.
For example:

FOR EACH customer :
    FUNCTION Foo RETURNS CHARACTER (city AS CHARACTER) :
    END FUNCTION.
END.

... because it is plain silly and ugly to do that, even if the compiler accepts it.
Functions (and procedures) should not be defined inside code blocks.

Compile will fail on Unix, use only lower-case includefiles

Rule "inclowercase" will raise this warning when it finds an include directive that has uppercase characters. For example:

   {subdirectory/IncludeFile.i}

The reason for this warning is that this sourcefile will not compile on Unix. Change the name to all lowercase so the source can be compiled on Unix and on Windows.
The assumption is of course, that sourcefiles are FTP'd to Unix with the "lowercase name conversion" option set in the FTP program.

Compile will fail on Unix, don't use backslash in includefiles

Rule "incslash" will raise this warning when it finds an include directive with backslashes. For example:

   {subdirectory\includefile.i}

The reason for this warning is that this sourcefile will not compile on Unix. Change the backslash into a forward slash so the source can be compiled on Unix and on Windows.

USING package, replace by USING type (without wildcards)

Rule "usingpkg" warns when it finds a USING statement with package globs. In other words:

USING package.ClassName

is recommended instead of:

USING package.*

The use of fully qualified class names, rather than package globs, seems to be a commonly preferred practice in other languages with similar language features.

replace public variable &1 by property

Rule "publicvar" gives this warning when it finds a DEFINE PUBLIC VARIABLE statement in a class. The statement should be replaced by a (public) PROPERTY.

Motivation

Encapsulation: a class is responsible for its own state. A public variable allows other objects and procedures outside the class to manipulate the state of the class, so that can't be right.