Add explicit advice for how to handle non-text strings.

PiperOrigin-RevId: 607101289
Change-Id: I09210fc433d0a37a9c08dabc7d2561adca412b96
diff --git a/api-guidelines/ b/api-guidelines/
index 4c46609..00f7815 100644
--- a/api-guidelines/
+++ b/api-guidelines/
@@ -297,6 +297,9 @@
     strongly preferred and any other choice should come with significant
+    If there is no encoding because the data is a string of arbitrary bytes, use
+    `uint8_t*` instead of `char*`. `char*` should only be used for text.
 6.  For NDK APIs, **documentation must be in Doxygen syntax.** To appear on DAC,
     all documentation (including `@file`) must be contained by a `@defgroup` or
     `@addtogroup` block.