Restrict channel names, too.

Thankfully, channel creation only happens in one place, so we don't need a state machine for this.

1 files changed, 13 insertions, 1 deletions

diff --git a/docs/api/channels-messages.md b/docs/api/channels-messages.md
index 9854d22..6391b5a 100644
--- a/docs/api/channels-messages.md
+++ b/docs/api/channels-messages.md
@@ -64,6 +64,14 @@ The request must have the following fields:
 |:-------|:-------|:--|
 | `name` | string | The channel's name. |
 
+The proposed `name` must be valid. The precise definition of valid is still up in the air, but, at minimum:
+
+* It must be non-empty.
+* It must not be "too long." (Currently, 64 characters is too long.)
+* It must begin with a printing character.
+* It must end with a printing character.
+* It must not contain runs of multiple whitespace characters.
+
 ### Success
 
 This endpoint will respond with a status of `202 Accepted` when successful. The body of the response will be a JSON object describing the new channel:
@@ -86,7 +94,11 @@ The returned name may not be identical to the name requested, as the name will b
 
 When completed, the service will emit a [channel created](events.md#channel-created) event with the channel's ID.
 
-### Duplicate channel name
+### Name not valid
+
+This endpoint will respond with a status of `400 Bad Request` if the proposed `name` is not valid.
+
+### Channel name in use
 
 This endpoint will respond with a status of `409 Conflict` if a channel with the requested name already exists.