diff --git a/Changelog.md b/Changelog.md
index 9b773689ce6..2360ede6f57 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -6,6 +6,16 @@
 
   * refactoring: Updating and simplifying the runtime system dependencies (#4677).
 
+* motoko-base
+
+  * Breaking change (minor): `Float.format(#hex)` is no longer supported.
+    This is because newer versions of Motoko (such as with enhanced orthogonal persistence)
+    rely on the Rust-native formatter that does not offer this functionality.
+    It is expected that this formatter is very rarely used in practice (dfinity/motoko-base⁠#589).
+
+  * Formatter change (minor): The text formatting of `NaN`, positive or negative,
+    will be `NaN` in newer Motoko versions, while it was `nan` or `-nan` in older versions (dfinity/motoko-base⁠#589).
+
 ## 0.13.3 (2024-11-13)
 
 * motoko (`moc`)
@@ -16,7 +26,7 @@
 * motoko-base
 
   * Add modules `OrderedMap` and `OrderedSet` to replace `RBTree` with improved functionality, performance
-    and ergonomics avoiding the need for preupgrade hooks (thanks to Serokell) (#662).
+    and ergonomics avoiding the need for preupgrade hooks (thanks to Serokell) (dfinity/motoko-base⁠#662).
 
 ## 0.13.2 (2024-10-18)
 
diff --git a/doc/md/base/Float.md b/doc/md/base/Float.md
index 6174070ecec..c7e02ca529b 100644
--- a/doc/md/base/Float.md
+++ b/doc/md/base/Float.md
@@ -480,7 +480,7 @@ Float.log(Float.e) // => 1.0
 
 ## Function `format`
 ``` motoko no-repl
-func format(fmt : {#fix : Nat8; #exp : Nat8; #gen : Nat8; #hex : Nat8; #exact}, x : Float) : Text
+func format(fmt : {#fix : Nat8; #exp : Nat8; #gen : Nat8; #exact}, x : Float) : Text
 ```
 
 Formatting. `format(fmt, x)` formats `x` to `Text` according to the
@@ -489,13 +489,15 @@ formatting directive `fmt`, which can take one of the following forms:
 * `#fix prec` as fixed-point format with `prec` digits
 * `#exp prec` as exponential format with `prec` digits
 * `#gen prec` as generic format with `prec` digits
-* `#hex prec` as hexadecimal format with `prec` digits
 * `#exact` as exact format that can be decoded without loss.
 
 `-0.0` is formatted with negative sign bit.
-Positive infinity is formatted as `inf`.
-Negative infinity is formatted as `-inf`.
-`NaN` is formatted as `NaN` or `-NaN` depending on its sign bit.
+Positive infinity is formatted as "inf".
+Negative infinity is formatted as "-inf".
+
+Note: The numerical precision and the text format can vary between
+Motoko versions and runtime configuration. Moreover, `NaN` can be printed
+differently, i.e. "NaN" or "nan", potentially omitting the `NaN` sign.
 
 Example:
 ```motoko