$text =~ s{$subsRE}{$replacementLU{ $1 }}g;

##</code><code>##

(?^:(?x) \b ( CONTENT_FILTERING_PROFILE_ID|QUOTA_GRANTED|ARP_VULNERABILITY|NETWORK_IDENTIFIER|ARP_PRIORITY_LEVEL|DEFAULT_BEARER_ID|EVENT_RESULT|EVENT_ID|QOS_PROFILE_ID|ARP_CAPABILITY|SYSTEM_IDENTIFIER|TRACKING_AREA_CODE|GX_RAR_RAA_TRANSACTION|SERVICE_AREA_CODE|RECORD_TYPE|RECORD_LENGTH|CHARGING_PROFILE_ID|QOS_ASSIGNED_TO_DEFAULT_BEARER|GX_CCR_CCA_TRANSACTION|RULE_REMOVED|BEARER_CONTROL_MODE|ROUTING_AREA_CODE|RULE_INSTALLED|CAUSE_PROTOCOL|SUBSCRIBERID ) \b)

##</code><code>##

qr{(?x) \b ( keys %replacementLU ) \b};

##</code><code>##

@{ [ keys %replacementLU ] }

##</code><code>##

$" = q{|};
my $subsRE = qr{(?x) \b ( @{ [ keys %replacementLU ] } ) \b};

##</code><code>##

my $subsRE = do {
   local $" = q{|};
   qr{(?x) \b ( @{ [ keys %replacementLU ] } ) \b};
   };