diff --git a/components/parameters/path/ExchangeId.yml b/components/parameters/path/ExchangeId.yml
new file mode 100644
index 00000000..5f58676e
--- /dev/null
+++ b/components/parameters/path/ExchangeId.yml
@@ -0,0 +1,8 @@
+name: exchange-id
+description: A potentially human-readable identifier for an exchange.
+in: path
+required: true
+schema:
+  type: string
+  minimum: 3
+  pattern: "[a-z0-9][a-z0-9\\-]{2,}"
diff --git a/components/parameters/path/TransactionUuid.yml b/components/parameters/path/TransactionUuid.yml
new file mode 100644
index 00000000..1aa2c3df
--- /dev/null
+++ b/components/parameters/path/TransactionUuid.yml
@@ -0,0 +1,6 @@
+in: path
+name: transaction-uuid
+required: true
+schema:
+  type: string
+  pattern: "([0-9a-f]{8}\b-[0-9a-f]{4}\b-[0-9a-f]{4}\b-[0-9a-f]{4}\b-[0-9a-f]{12}){0,1}"
diff --git a/holder.yml b/holder.yml
index 01e461d2..9ea01a28 100644
--- a/holder.yml
+++ b/holder.yml
@@ -67,13 +67,7 @@ paths:
         the request, it returns a Verifiable Presentation Request. A request
         that the server cannot understand results in an error.
       parameters:
-        - in: path
-          name: exchange-id
-          required: true
-          schema:
-            type: string
-            minimum: 3
-            pattern: "[a-z0-9\\-]{3,}"
+        - $ref: "./components/parameters/path/ExchangeId.yml"
       requestBody:
         description:
           Information related to the type of exchange the client would like
@@ -120,20 +114,8 @@ paths:
         Presentation Request. A request that the server cannot understand
         results in an error.
       parameters:
-        - in: path
-          name: exchange-id
-          description:
-            A human readable exchange type identifier such as "diplomas".
-          required: true
-          schema:
-            type: string
-            pattern: "[a-z0-9\\-]{3,}"
-        - in: path
-          name: transaction-uuid
-          required: true
-          schema:
-            type: string
-            pattern: "([0-9a-f]{8}\b-[0-9a-f]{4}\b-[0-9a-f]{4}\b-[0-9a-f]{4}\b-[0-9a-f]{12}){0,1}"
+        - $ref: "./components/parameters/path/ExchangeId.yml"
+        - $ref: "./components/parameters/path/TransactionUuid.yml"
       requestBody:
         description:
           A Verifiable Presentation.