This might provide some insight:

$ perl -wE 'say hex 0xAf; say hex q{0xAf}; say hex qq{0xAf};'
373
175
175

$ perl -wE 'say sprintf q{%s}, 0xAf; say sprintf q{%s}, q{0xAf}; say s
+printf q{%s}, qq{0xAf};'
175
0xAf
0xAf

$ perl -wE 'say hex 175'
373

$ perl -wE 'say oct 0xAf; say oct q{0xAf}; say oct qq{0xAf};'
125
175
175

$ perl -wE 'say oct 175'
125
[download]

In oct it says: "If EXPR happens to start off with 0x , interprets it as a hex string."

Just for reference, here's the hex link.