 
                            Perl 4 used ' as a package name separator when importing packages. Perl 5 provides the same feature, but uses :: to separate package names. Use colons rather than quotes to separate packages.
Noncompliant Code Example
This noncompliant code example uses the Perl 4 ' syntax to import an external package. This code does successfully require the package, but because Perl 5 is over 15 years old, the Perl 4 syntax has largely been forgotten. Consequently, the code can be seen as confusing or arcane.
require DBI'SQL'Nano;
Compliant Solution
This compliant solution uses Perl 5's :: syntax to import an external package:
require DBI::SQL::Nano;
Risk Assessment
| Recommendation | Severity | Likelihood | Remediation Cost | Priority | Level | 
|---|---|---|---|---|---|
| DCL04-PL | low | improbable | low | P3 | L1 | 
Automated Detection
| Tool | Diagnostic | 
| Perl::Critic | Variables::ProhibitPerl4PackageNames | 
Bibliography
[CPAN] Elliot Shank, Perl-Critic-1.116 Variables::ProhibitPerl4PackageNames