Internally
>perl -MDevel::Peek -e"Dump(qq{\x{C2AE}});"     __ encoded
SV = PV(0x23734c) at 0x235fc0                  /   as UTF-8
  REFCNT = 1                                  /
  FLAGS = (PADBUSY,PADTMP,POK,READONLY,pPOK,UTF8)
  PV = 0x182f574 "\354\212\256"\0 [UTF8 "\x{c2ae}"]
  CUR = 3         -----v------           ---v----
  LEN = 4               \                    \____ String
                         \
                          \_______________________ Internal
                                                   encoding
                                                   (bytes)
>perl -MDevel::Peek -e"Dump('abc');"
SV = PV(0x236e00) at 0x182f778
  REFCNT = 1
  FLAGS = (PADBUSY,PADTMP,POK,READONLY,pPOK)
  PV = 0x182f56c "abc"\0
  CUR = 3         -v-         Bytes treated as
  LEN = 4           \________ iso-latin-1 by
                              perl functions

##</code><code>##

>perl -MDevel::Peek -e"Dump(qq{\x{05D0}\x{20AC}});"
SV = PV(0x237354) at 0x235fc8
  REFCNT = 1
  FLAGS = (PADBUSY,PADTMP,POK,READONLY,pPOK,UTF8)
  PV = 0x18307bc "\327\220\342\202\254"\0 [UTF8 "\x{5d0}\x{20ac}"]
  CUR = 5
  LEN = 8

>perl -MDevel::Peek -e"Dump(qq{\x05\xD0\x20\xAC});"
SV = PV(0x237354) at 0x235fc8
  REFCNT = 1
  FLAGS = (PADBUSY,PADTMP,POK,READONLY,pPOK)
  PV = 0x18307bc "\5\320 \254"\0
  CUR = 4
  LEN = 8