diff --git a/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientRequestContext.java b/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientRequestContext.java
index 70e7af5..cf56f69 100644
--- a/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientRequestContext.java
+++ b/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientRequestContext.java
@@ -201,13 +201,13 @@
      * class or using its {@code toString} method if a header delegate is not available.
      *
      * <p>
-     * For example: {@code containsHeaderString("cache-control", null, "no-store"::equalsIgnoreCase)} will return {@code true} if
+     * For example: {@code containsHeaderString("cache-control", ",", "no-store"::equalsIgnoreCase)} will return {@code true} if
      * a {@code Cache-Control} header exists that has the value {@code no-store}, the value {@code No-Store} or the value
      * {@code Max-Age, NO-STORE, no-transform}, but {@code false} when it has the value {@code no-store;no-transform}
      * (missing comma), or the value {@code no - store} (whitespace within value).
      *
      * @param name the message header.
-     * @param valueSeparatorRegex Separates the header value into single values. Defaults to {@code \s*,\s*} when {@code null}.
+     * @param valueSeparatorRegex Separates the header value into single values. {@code null} does not split.
      * @param valuePredicate value must fulfil this predicate.
      * @return {@code true} if and only if a header with the given name exists, having either a whitespace-trimmed value
      * matching the predicate, or having at least one whitespace-trimmed single value in a comma-separated list of single values.
diff --git a/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientResponseContext.java b/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientResponseContext.java
index 8abcc0b..7956d31 100644
--- a/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientResponseContext.java
+++ b/jaxrs-api/src/main/java/jakarta/ws/rs/client/ClientResponseContext.java
@@ -93,13 +93,13 @@
      * Checks whether a header with a specific name and value (or item of the comma-separated value list) exists.
      *
      * <p>
-     * For example: {@code containsHeaderString("cache-control", null, "no-store"::equalsIgnoreCase)} will return {@code true} if
+     * For example: {@code containsHeaderString("cache-control", ",", "no-store"::equalsIgnoreCase)} will return {@code true} if
      * a {@code Cache-Control} header exists that has the value {@code no-store}, the value {@code No-Store} or the value
      * {@code Max-Age, NO-STORE, no-transform}, but {@code false} when it has the value {@code no-store;no-transform}
      * (missing comma), or the value {@code no - store} (whitespace within value).
      *
      * @param name the message header.
-     * @param valueSeparatorRegex Separates the header value into single values. Defaults to {@code \s*,\s*} when {@code null}.
+     * @param valueSeparatorRegex Separates the header value into single values. {@code null} does not split.
      * @param valuePredicate value must fulfil this predicate.
      * @return {@code true} if and only if a header with the given name exists, having either a whitespace-trimmed value
      * matching the predicate, or having at least one whitespace-trimmed single value in a comma-separated list of single values.
diff --git a/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerRequestContext.java b/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerRequestContext.java
index b755913..6046edf 100644
--- a/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerRequestContext.java
+++ b/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerRequestContext.java
@@ -233,13 +233,13 @@
      * Checks whether a header with a specific name and value (or item of the comma-separated value list) exists.
      *
      * <p>
-     * For example: {@code containsHeaderString("cache-control", null, "no-store"::equalsIgnoreCase)} will return {@code true} if
+     * For example: {@code containsHeaderString("cache-control", ",", "no-store"::equalsIgnoreCase)} will return {@code true} if
      * a {@code Cache-Control} header exists that has the value {@code no-store}, the value {@code No-Store} or the value
      * {@code Max-Age, NO-STORE, no-transform}, but {@code false} when it has the value {@code no-store;no-transform}
      * (missing comma), or the value {@code no - store} (whitespace within value).
      *
      * @param name the message header.
-     * @param valueSeparatorRegex Separates the header value into single values. Defaults to {@code \s*,\s*} when {@code null}.
+     * @param valueSeparatorRegex Separates the header value into single values. {@code null} does not split.
      * @param valuePredicate value must fulfil this predicate.
      * @return {@code true} if and only if a header with the given name exists, having either a whitespace-trimmed value
      * matching the predicate, or having at least one whitespace-trimmed single value in a comma-separated list of single values.
diff --git a/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerResponseContext.java b/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerResponseContext.java
index 936f5cc..cfd5d70 100644
--- a/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerResponseContext.java
+++ b/jaxrs-api/src/main/java/jakarta/ws/rs/container/ContainerResponseContext.java
@@ -123,13 +123,13 @@
      * class or using its {@code toString} method if a header delegate is not available.
      *
      * <p>
-     * For example: {@code containsHeaderString("cache-control", null, "no-store"::equalsIgnoreCase)} will return {@code true} if
+     * For example: {@code containsHeaderString("cache-control", ",", "no-store"::equalsIgnoreCase)} will return {@code true} if
      * a {@code Cache-Control} header exists that has the value {@code no-store}, the value {@code No-Store} or the value
      * {@code Max-Age, NO-STORE, no-transform}, but {@code false} when it has the value {@code no-store;no-transform}
      * (missing comma), or the value {@code no - store} (whitespace within value).
      *
      * @param name the message header.
-     * @param valueSeparatorRegex Separates the header value into single values. Defaults to {@code \s*,\s*} when {@code null}.
+     * @param valueSeparatorRegex Separates the header value into single values. {@code null} does not split.
      * @param valuePredicate value must fulfil this predicate.
      * @return {@code true} if and only if a header with the given name exists, having either a whitespace-trimmed value
      * matching the predicate, or having at least one whitespace-trimmed single value in a comma-separated list of single values.
diff --git a/jaxrs-api/src/main/java/jakarta/ws/rs/core/HttpHeaders.java b/jaxrs-api/src/main/java/jakarta/ws/rs/core/HttpHeaders.java
index 8895d75..c814e6c 100644
--- a/jaxrs-api/src/main/java/jakarta/ws/rs/core/HttpHeaders.java
+++ b/jaxrs-api/src/main/java/jakarta/ws/rs/core/HttpHeaders.java
@@ -69,13 +69,13 @@
      * class or using its {@code toString} method if a header delegate is not available.
      *
      * <p>
-     * For example: {@code containsHeaderString("cache-control", null, "no-store"::equalsIgnoreCase)} will return {@code true} if
+     * For example: {@code containsHeaderString("cache-control", ",", "no-store"::equalsIgnoreCase)} will return {@code true} if
      * a {@code Cache-Control} header exists that has the value {@code no-store}, the value {@code No-Store} or the value
      * {@code Max-Age, NO-STORE, no-transform}, but {@code false} when it has the value {@code no-store;no-transform}
      * (missing comma), or the value {@code no - store} (whitespace within value).
      *
      * @param name the message header.
-     * @param valueSeparatorRegex Separates the header value into single values. Defaults to {@code \s*,\s*} when {@code null}.
+     * @param valueSeparatorRegex Separates the header value into single values. {@code null} does not split.
      * @param valuePredicate value must fulfil this predicate.
      * @return {@code true} if and only if a header with the given name exists, having either a whitespace-trimmed value
      * matching the predicate, or having at least one whitespace-trimmed single value in a comma-separated list of single values.