$ cpanp
CPANPLUS::Shell::Default -- CPAN exploration and module installation (v0.88)
[snip]
CPAN Terminal> install Scalar-List-Utils

[ERROR] 'Scalar-List-Utils' does not contain an author part

[ERROR] Cannot find 'Scalar-List-Utils' in the module tree

No such module: Scalar-List-Utils
No modules found to operate on!
Nothing done

##</code><code>##

parse_module tries to find a CPANPLUS::Module object that matches your query. Here's a list of examples you could give to parse_module;

Text::Bastardize
Text-Bastardize
Text-Bastardize-1.06
AYRNIEU/Text-Bastardize
AYRNIEU/Text-Bastardize-1.06
AYRNIEU/Text-Bastardize-1.06.tar.gz
http://example.com/Text-Bastardize-1.06.tar.gz
file:///tmp/Text-Bastardize-1.06.tar.gz
/tmp/Text-Bastardize-1.06
./Text-Bastardize-1.06 

##</code><code>##

@mods can be a list of distribution names, module names or module objects, basically anything that parse_module can understand.