diff --git a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
index 967a10795..97110c608 100644
--- a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
+++ b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
@@ -41,8 +41,6 @@ import org.springframework.util.CollectionUtils;
  */
 class BindableFunctionProxyFactory extends BindableProxyFactory {
 
-	static final String delimiter = "-";
-
 	private final int inputCount;
 
 	private final int outputCount;
@@ -128,18 +126,18 @@ class BindableFunctionProxyFactory extends BindableProxyFactory {
 
 	private String buildInputNameForIndex(int index) {
 		return new StringBuilder(this.functionDefinition)
-			.append(delimiter)
-			.append("in")
-			.append(delimiter)
+			.append(FunctionConstants.DELIMITER)
+			.append(FunctionConstants.DEFAULT_INPUT_SUFFIX)
+			.append(FunctionConstants.DELIMITER)
 			.append(index)
 			.toString();
 	}
 
 	private String buildOutputNameForIndex(int index) {
 		return new StringBuilder(this.functionDefinition)
-				.append(delimiter)
-				.append("out")
-				.append(delimiter)
+				.append(FunctionConstants.DELIMITER)
+				.append(FunctionConstants.DEFAULT_OUTPUT_SUFFIX)
+				.append(FunctionConstants.DELIMITER)
 				.append(index)
 				.toString();
 	}
diff --git a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConstants.java b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConstants.java
new file mode 100644
index 000000000..74180db3b
--- /dev/null
+++ b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConstants.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2019-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.stream.function;
+
+/**
+ * Interfaces which defines constants used for naming conventions used in bindings
+ * of multiple functions or functions with multiple inputs and outputs.
+ *
+ * @author Oleg Zhurakousky
+ * @author Soby Chacko
+ *
+ * @since 3.0
+ *
+ */
+public final class FunctionConstants {
+
+	private FunctionConstants() {
+
+	}
+
+	/**
+	 * Delimiter used for functional binding naming convention.
+	 */
+	public static final String DELIMITER = "-";
+
+	/**
+	 * Suffix used for functional binding naming convention.
+	 */
+	public static final String DEFAULT_OUTPUT_SUFFIX = "out";
+
+	/**
+	 * Prefix used for functional binding naming convention.
+	 */
+	public static final String DEFAULT_INPUT_SUFFIX = "in";
+}