a @kbd{C-u}, precisely. Any other sort of argument, including @kbd{C-u}
and digits, specifies an earlier kill to yank (@pxref{Earlier Kills}).
+@cindex yanking and text properties
+@vindex yank-excluded-properties
+ The yank commands discard certain text properties from the text that
+is yanked, those that might lead to annoying results. For instance,
+they discard text properties that respond to the mouse or specify key
+bindings. The variable @code{yank-excluded-properties} specifies the
+properties to discard. Yanking of register contents and rectangles
+also discard these properties.
+
@kindex M-w
@findex kill-ring-save
To copy a block of text, you can use @kbd{M-w}