markdown: fix the channel icon docs for the current code, fixes #4493

diff --git a/docs/property/config_channelicon_path.md b/docs/property/config_channelicon_path.md
index 15d14dd430ed3499a240c06783ab31794a9873ae..33ee5b6b2d730cc0700afbbac8c6c0e047c06306 100644 (file)
--- a/docs/property/config_channelicon_path.md
+++ b/docs/property/config_channelicon_path.md
@@ -4,7 +4,15 @@ The following placeholders are available:
 
 Placeholder | Function
 :----------:| --------
-**%C**      | The transliterated channel name in ASCII (safe characters, no spaces, etc. - so `Das Erste HD` will be `Das_Erste_HD`, but `WDR Köln` will be `WDR_Koln`)
-**%c**      | The channel name (URL encoded ASCII)
+**%C**      | The transliterated channel name in in URL encoded ASCII with safe characters only - `WDR Köln :<>|*?'"` will be `WDR%20Koln%20________`
+**%c**      | The channel name (URL encoded UTF-8)
 
 Example: `file:///tmp/icons/%C.png` or `http://example.com/%c.png`
+
+Note: The `file://` URLs are deescaped back when used, so `%20` means space
+for the filename for example.
+
+Safety note: For the channel name, the first dot characters (possible
+hidden files or special directories) are replaced with the underscore
+character. The possible directory delimiters (slash) and the special
+character backslash are replaced with the minus character.