diff --git a/docs/mediums/identity.md b/docs/mediums/identity.md
deleted file mode 100644
index 43dc0e4..0000000
--- a/docs/mediums/identity.md
+++ /dev/null
@@ -1 +0,0 @@
-# Identity
diff --git a/docs/mediums/membership.md b/docs/mediums/membership.md
new file mode 100644
index 0000000..b46c2a9
--- /dev/null
+++ b/docs/mediums/membership.md
@@ -0,0 +1,35 @@
+# Membership
+
+Membership is a means by which an organization or government determines its core constituency---and excludes non-members. Members enjoy some specific set of rights of governance and benefit that non-members do not enjoy. In state contexts, it is generally referred to as citizenship. In corporate contexts, it may correlate with stock [ownership](ownership.md). Systems of membership typically presume some means of identity management.
+
+**Input:** identity management, set of membership rights and benefits
+
+**Output:** enjoyment of rights and benefits by members
+
+## Background
+
+<!-- brief historical reference points -->
+
+## Feedback loops
+
+### Sensitivities
+
+<!-- what does this medium capture especially well? -->
+
+### Oversights
+
+<!-- what does this medium overlook? -->
+
+## Implementations
+
+### Communities
+
+<!-- what are some real-world examples in practice? -->
+
+### Tools
+
+<!-- what software, methodologies, or organizations are available to facilitate implementation -->
+
+## Further resources
+
+<!-- where should people look first if they want to learn more? -->