Improve documentation of 'decode-coding-region'

* src/coding.c (Fdecode_coding_region): Doc fix.

* doc/lispref/nonascii.texi (Coding System Basics)
(Explicit Encoding): Explain the significance of using 'undecided'
in 'decode-coding-*' functions.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/coding.c b/src/coding.c
index 7030a53869a..02dccf5bdb0 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -9455,11 +9455,12 @@ code_convert_region (Lisp_Object start, Lisp_Object end,
 DEFUN ("decode-coding-region", Fdecode_coding_region, Sdecode_coding_region,
        3, 4, "r\nzCoding system: ",
        doc: /* Decode the current region from the specified coding system.
+Interactively, prompt for the coding system to decode the region.
 
-What's meant by \"decoding\" is transforming bytes into text
-(characters).  If, for instance, you have a region that contains data
-that represents the two bytes #xc2 #xa9, after calling this function
-with the utf-8 coding system, the region will contain the single
+\"Decoding\" means transforming bytes into readable text (characters).
+If, for instance, you have a region that contains data that represents
+the two bytes #xc2 #xa9, after calling this function with the utf-8
+coding system, the region will contain the single
 character ?\\N{COPYRIGHT SIGN}.
 
 When called from a program, takes four arguments: