All scalar variables are really only references to SVs. (There's a similar relation between arrays and AVs, hashes and HVs, etc.) Sometimes Perl creates SVs to which no variable refers, and it's possible to create more than one variable that refers to the same SV.

   +------------+      references (1:1)      +------------+
   | Lexical or |  ----------------------->  |            |
   | Package    |                            |     SV     |
   | Scalar Var |     referenced by (1:N)    |            |
   +------------+  <-----------------------  +------------+
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The "anonymous values" are simply SVs.