diff --git a/matrix/nginx/workers/README.md b/matrix/nginx/workers/README.md
index 1f9b8ab..2f8a9e5 100644
--- a/matrix/nginx/workers/README.md
+++ b/matrix/nginx/workers/README.md
@@ -14,12 +14,12 @@ changing from network sockets to UNIX sockets.
 Because we're going to have to forward a lot of specific requests to all kinds
 of workers, we'll split the configuration into a few bits:
 
-** all `proxy_forward` settings
-** all `location` definitions
-** maps that define variables
-** upstreams that point to the correct socket(s) with the correct settings
-** settings for private access
-** connection optimizations
+* all `proxy_forward` settings
+* all `location` definitions
+* maps that define variables
+* upstreams that point to the correct socket(s) with the correct settings
+* settings for private access
+* connection optimizations
 
 Some of these go into `/etc/nginx/conf.d` because they are part of the
 configuration of nginx itself, others go into `/etc/nginx/snippets` because we
@@ -60,3 +60,14 @@ map $arg_since $sync {
 We filter the argument `since` by using `$arg_since`, see [the index of
 variables in nginx](https://nginx.org/en/docs/varindex.html) for more
 variables we can use.
+
+By default we set `$sync` to `normal_sync`, unless the argument `since` is
+empty (absent); then we set `$sync` to `initial_sync`.
+
+After that, we forward the request:
+
+```
+proxy_pass http://$sync;
+```
+
+