I am enforcing some rules are CRM tags and the regexps are pushing my limits. So, a follow up to a little question over at Re^3: regex in REPLACEMENT in s///

Part A

I have never got chomp to work so I avoid it...

my $tag = 'test text     ';
chomp $tag;
print $tag . '#';

> test text     #

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I understood it to equivalent to s/ +$//; when used as above with no new lines.

Part B

The tags should be lowercase and exclude most punctuation. Extraneous punctuation removed and uppercase characters converted to lowercase. Here is what I have tried 

$tag =  lc $tag;
$tag =~ s/[^az09 _\-\+\.]//g;

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I expected the regexp to substitute anything that is not ^ in the character class [] with an empty string. But it seems to strip out anything that is not an 'a' character or a space.

How should I go about properly working out how to construct a regexp to do what I want?

In reply to chomp and regexp by Bod

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