diff --git a/custom/conf/app.ini.sample b/custom/conf/app.ini.sample
index 442ac4b5bb9d..5ee2162ba355 100644
--- a/custom/conf/app.ini.sample
+++ b/custom/conf/app.ini.sample
@@ -141,8 +141,9 @@ KEYWORDS = go,git,self-hosted,gitea
 [markdown]
 ; Enable hard line break extension
 ENABLE_HARD_LINE_BREAK = false
-; List of custom URL-Schemes that are allowed as links when rendering Markdown
-; for example git,magnet
+; Comma separated list of custom URL-Schemes that are allowed as links when rendering Markdown
+; for example git,magnet,ftp (more at https://en.wikipedia.org/wiki/List_of_URI_schemes)
+; URLs starting with http and https are always displayed, whatever is put in this entry.
 CUSTOM_URL_SCHEMES =
 ; List of file extensions that should be rendered/edited as Markdown
 ; Separate the extensions with a comma. To render files without any extension as markdown, just put a comma
@@ -826,4 +827,4 @@ QUEUE_TYPE = channel
 QUEUE_LENGTH = 1000
 ; Task queue connction string, available only when `QUEUE_TYPE` is `redis`. 
 ; If there is a password of redis, use `addrs=127.0.0.1:6379 password=123 db=0`.
-QUEUE_CONN_STR = "addrs=127.0.0.1:6379 db=0"
\ No newline at end of file
+QUEUE_CONN_STR = "addrs=127.0.0.1:6379 db=0"