diff --git a/STYLEGUIDE.md b/STYLEGUIDE.md
index 18f6dc4..5b49ef4 100644
--- a/STYLEGUIDE.md
+++ b/STYLEGUIDE.md
@@ -20,6 +20,12 @@
 - A PR that is in-progress should have `[wip]` in front of the PR's title. When
   ready for review, remove the `[wip]` and ping a core contributor with an `@`.
 
+- Forcing PRs to be small can have the effect of users submitting PRs in a hierarchical chain, with
+  one depending on the next. If a PR depends on another one, it should have a [Pending #PRNUM]
+  prefix in the PR title. In addition, it will be the PR submitter's responsibility to remove the
+  [Pending #PRNUM] tag once the PR has been updated with the merged, dependent PR. That will
+  let reviewers know it is ready to review.
+
 - A PR should be small. Even if you intend on implementing an entire
   service, a PR should only be one route of that service
   (e.g. create server or get server, but not both).