diff --git a/CHARTER.md b/CHARTER.md
index 52a960ed2..fdc1645fb 100644
--- a/CHARTER.md
+++ b/CHARTER.md
@@ -4,7 +4,7 @@ This charter describes the stewardship pattern that applies to every standard pu
 
 ## The pattern
 
-Each standard in this repository is published under an open licence — Apache-2.0 for code, CC-BY-4.0 for specification text — and is owned by no one. Transaction Science writes the reference implementation, runs the optional hosted services, and stewards the conformance vectors. The wire format and the right to fork are public.
+Each standard in this repository is published under an open licence — Apache-2.0 for code, CC-BY-4.0 for specification text, except WAI, whose specification text is Apache-2.0 too — and is owned by no one. Transaction Science writes the reference implementation, runs the optional hosted services, and stewards the conformance vectors. The wire format and the right to fork are public.
 
 This is the difference between **the protocol** and **the offer**:
 
diff --git a/wai/README.md b/wai/README.md
index 883cd18eb..de645967d 100644
--- a/wai/README.md
+++ b/wai/README.md
@@ -1,4 +1,4 @@
-# WAI — Web AI Media Transport & Execution
+# .WAI™ — Web AI Media Transport & Execution
 
 A container + capability-dispatch standard for media. A standard codec
 (AVIF, JPEG XL, PNG, JPEG, Opus, FLAC, AV1, zstd, XZ and the others the
diff --git a/wai/SPEC.md b/wai/SPEC.md
index c850e97bb..3298f8238 100644
--- a/wai/SPEC.md
+++ b/wai/SPEC.md
@@ -1,4 +1,4 @@
-# WAI v1.0 — Web AI Media Transport & Execution
+# .WAI™ v1.0 — Web AI Media Transport & Execution
 
 Status: **Draft Standard**. Reference implementation: `wai-rs/` (Rust
 lib + cdylib + staticlib, C FFI). Two paths open every conforming
@@ -3826,4 +3826,5 @@ specifies.
 Apache-2.0. The standard and the reference implementation are open;
 royalty-free implementation is a precondition for adoption, so every default
 capability (§5) is royalty-free. Companion implementations outside this tree
-keep their own licences.
+keep their own licences. The licence does not cover the marks: see
+[`TRADEMARKS.md`](TRADEMARKS.md).
diff --git a/wai/TRADEMARKS.md b/wai/TRADEMARKS.md
new file mode 100644
index 000000000..74de84a55
--- /dev/null
+++ b/wai/TRADEMARKS.md
@@ -0,0 +1,26 @@
+# The marks
+
+`.WAI™`, `WA²ISM™` and `WAISM™` are trademarks of Transaction Science, Inc.
+
+- **`.WAI™`** is the name of the format and its toolchain, from Transaction Science.
+- **`WA²ISM™`**, also written `WAISM™`, is the name of the deterministic WebAssembly
+  module profile.
+
+## What you may do without asking
+
+The Apache License 2.0 covers the specification and the code. Section 6 of that licence
+does not grant the marks. Anyone may, without asking:
+
+- use the plain name WAI, the `.wai` file extension and every identifier the
+  specification defines, in code, files, documentation and conversation;
+- say accurately that a product reads or writes `.wai` files, implements the
+  specification, or passes `wai conform`;
+- fork and change the specification and the code, as the licence allows.
+
+## What needs permission
+
+- Naming a product, service, company or domain with one of the marks.
+- Calling a changed specification or a fork by one of the marks.
+- Implying that Transaction Science made, certified or endorses something it did not.
+
+Write to hello@transaction.science.
diff --git a/wai/changes/2026-11-05-marks.md b/wai/changes/2026-11-05-marks.md
new file mode 100644
index 000000000..6fcc05f4e
--- /dev/null
+++ b/wai/changes/2026-11-05-marks.md
@@ -0,0 +1,7 @@
+### The marks
+
+- `.WAI™`, `WA²ISM™` and `WAISM™` are named as trademarks of Transaction Science, Inc., in
+  `TRADEMARKS.md`, which also says what anyone may do without asking. The README's and the
+  specification's titles carry `.WAI™`.
+- `CHARTER.md` states that WAI's specification text is Apache-2.0, as Appendix C of the
+  specification and `wai/LICENSE` already say.