diff --git a/README.md b/README.md
index 9a862f6..21d83cd 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,10 @@ Search and replace all mentions of FIXME with sensible content in this file and
 
 Docker Compose files to spin up an instance of Nginx.
 
+Nginx comes with an optional sidecar container we're calling `ping` whose purpose is to do health checks. If you want Nginx to bind to a specific virtual IP address you're going to want to use `ping`, it will quite literally ping the virtual IP address for you and report a successful health check once the address becomes reachable. Only then will Nginx start up. Management on your Docker host of a virtual IP address can happen via `iproute2`/`ip addr add`, `keepalived` or similar mechanisms and is out of scope of this repository.
+
+Feel free to run Nginx without `ping` if you have no need for a virtual IP address. Continue reading for details on how to start with and without the `ping` sidecar container.
+
 # How to run
 
 Add a `COMPOSE_ENV` file and save its location as a shell variable along with the location where this repo lives, here for example `/opt/containers/nginx` plus all other variables. At [env/fqdn_context.env.example](env/fqdn_context.env.example) you'll find an example environment file.