*: always backquote stdin, stdout and stderr (#9584)

pages/common/base64.md

@@ -3,18 +3,18 @@
 > Encode or decode file or standard input to/from Base64, to standard output.
 > More information: <https://www.gnu.org/software/coreutils/base64>.
 
-- Encode the contents of a file as base64 and write the result to stdout:
+- Encode the contents of a file as base64 and write the result to `stdout`:
 
 `base64 {{filename}}`
 
-- Decode the base64 contents of a file and write the result to stdout:
+- Decode the base64 contents of a file and write the result to `stdout`:
 
 `base64 --decode {{filename}}`
 
-- Encode from stdin:
+- Encode from `stdin`:
 
 `{{somecommand}} | base64`
 
-- Decode from stdin:
+- Decode from `stdin`:
 
 `{{somecommand}} | base64 --decode`