--- /dev/null
+package SL::Helper::UNECERecommendation20;
+
+use strict;
+use warnings;
+use utf8;
+
+use Exporter qw(import);
+our @EXPORT_OK = qw(map_name_to_alpha_2_code);
+
+use List::Util qw(first);
+
+my @mappings = (
+ # areas
+ [ 'MTK', qr{^(?:m²|qm|quadrat *meter|quadrat *metre)$}i ],
+
+ # distances
+ [ 'CMT', qr{^(?:cm|centi *meter|centi *metre)$}i ],
+ [ 'MTR', qr{^(?:m|meter|metre)$}i ],
+ [ 'KMT', qr{^(?:km|kilo *meter|kilo *metre)$}i ],
+
+ # durations
+ [ 'SEC', qr{^(?:s|sec|second|sek|sekunde)$}i ],
+ [ 'MIN', qr{^min(?:ute)?$}i ],
+ [ 'MON', qr{^mon(?:th|at)?$}i ],
+ [ 'HUR', qr{^(?:h(?:our)?|std(?:unde)?)$}i ],
+ [ 'DAY', qr{^(?:day|tag)$}i ],
+
+ # mass
+ [ 'MGM', qr{^(?:mg|milli *gramm?)$}i ],
+ [ 'GRM', qr{^(?:g|gramm?)$}i ],
+ [ 'KGM', qr{^(?:kg|kilo *gramm?)$}i ],
+ [ 'KTN', qr{^(?:t|tonne|kilo *tonne)$}i ],
+
+ # volumes
+ [ 'MLT', qr{^(?:ml|milli *liter|milli *litre)$}i ],
+ [ 'LTR', qr{^(?:l|liter|litre)$}i ],
+
+ # miscellaneous
+ [ 'C62', qr{^(?:stck|stück|pieces?|pc|psch|pauschal)$}i ],
+);
+
+sub map_name_to_code {
+ my ($unit) = @_;
+
+ return undef if ($unit // '') eq '';
+
+ my $code = first { $unit =~ $_->[1] } @mappings;
+ return $code->[0] if $code;
+
+ no warnings 'once';
+ $::lxdebug->message(LXDebug::WARN(), "UNECERecommendation20::map_name_code: no mapping found for '$unit'");
+
+ return undef;
+}
+
+1;