'/(?;x/' => 'Sequence (?;...) not recognized in regex; marked by {#} in m/(?;{#}x/',
'/(?<;x/' => 'Sequence (?<;...) not recognized in regex; marked by {#} in m/(?<;{#}x/',
+ '/(?\ix/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}ix/',
+ '/(?\mx/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}mx/',
+ '/(?\:x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}:x/',
+ '/(?\=x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}=x/',
+ '/(?\!x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}!x/',
+ '/(?\<=x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}<=x/',
+ '/(?\<!x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}<!x/',
+ '/(?\>x/' => 'Sequence (?\...) not recognized in regex; marked by {#} in m/(?\{#}>x/',
+
'/((x)/' => 'Unmatched ( in regex; marked by {#} in m/({#}(x)/',
"/x{$inf_p1}/" => "Quantifier in {,} bigger than $inf_m1 in regex; marked by {#} in m/x{{#}$inf_p1}/",