Use MSC number

proposals/3999-timestamp-to-event-causal-parameter.md

@@ -1,4 +1,4 @@
-# MSCXXXX: Add causal parameter to `/timestamp_to_event`
+# MSC3999: Add causal parameter to `/timestamp_to_event`
 
 Causality just means being able to know "A happened before B" or vice versa.
 
@@ -35,7 +35,7 @@ before or after from (a casual relationship).
    `ts` looking backwards before `event_id`
 
 It essentially acts as a signal to keep progressing from this event regardless of what
-timestamp shenagins are going on.
+timestamp shenanigans are going on.
 
 
 ### Further explanation/example
@@ -103,19 +103,19 @@ No extra data is exposed. It's just a new way to filter it down and sort through
 ## Unstable prefix
 
 While this feature is in development, the `event_id` querystring parameter can be used as
-`org.matrix.mscXXXX.event_id`
+`org.matrix.msc3999.event_id`
 
 ### While the MSC is unstable
 
 During this period, to detect server support clients should check for the presence of
-the `org.matrix.mscXXXX` flag in `unstable_features` on `/versions`. Clients are also
+the `org.matrix.msc3999` flag in `unstable_features` on `/versions`. Clients are also
 required to use the unstable prefixes (see [unstable prefix](#unstable-prefix)) during
 this time.
 
 ### Once the MSC is merged but not in a spec version
 
 Once this MSC is merged, but is not yet part of the spec, clients should rely on the
-presence of the `org.matrix.mscXXXX.stable` flag in `unstable_features` to determine
+presence of the `org.matrix.msc3999.stable` flag in `unstable_features` to determine
 server support. If the flag is present, clients are required to use stable prefixes (see
 [unstable prefix](#unstable-prefix)).
 
@@ -123,7 +123,7 @@ server support. If the flag is present, clients are required to use stable prefi
 
 Once this MSC becomes a part of a spec version, clients should rely on the presence of
 the spec version, that supports the MSC, in `versions` on `/versions`, to determine
-support. Servers are encouraged to keep the `org.matrix.mscXXXX.stable` flag around for
+support. Servers are encouraged to keep the `org.matrix.ms3999.stable` flag around for
 a reasonable amount of time to help smooth over the transition for clients. "Reasonable"
 is intentionally left as an implementation detail, however the MSC process currently
 recommends *at most* 2 months from the date of spec release.