diff --git a/best-practices/massive-regions-best-practices.md b/best-practices/massive-regions-best-practices.md
index 8389f8d6b2e8e..df3e5df18e088 100644
--- a/best-practices/massive-regions-best-practices.md
+++ b/best-practices/massive-regions-best-practices.md
@@ -142,7 +142,7 @@ The default size of a Region is 256 MiB, and you can reduce the number of Region
 
 > **Note:**
 >
-> The default size of Region is enlarged to 256 MiB since TiDB v8.3.0.
+> The default size of Region is enlarged to 256 MiB since TiDB v8.4.0.
 
 > **Warning:**
 >
diff --git a/best-practices/pd-scheduling-best-practices.md b/best-practices/pd-scheduling-best-practices.md
index 5c4197593faf1..4733c40e78583 100644
--- a/best-practices/pd-scheduling-best-practices.md
+++ b/best-practices/pd-scheduling-best-practices.md
@@ -104,9 +104,9 @@ Region merge refers to the process of merging adjacent small regions. It serves
 
 Specifically, when a newly split Region exists for more than the value of [`split-merge-interval`](/pd-configuration-file.md#split-merge-interval) (`1h` by default), if the following conditions occur at the same time, this Region triggers the Region merge scheduling:
 
-- The size of this Region is smaller than the value of the [`max-merge-region-size`](/pd-configuration-file.md#max-merge-region-size) (Change to 54 MiB by default since v8.3.0, automatically applied only for newly created clusters).
+- The size of this Region is smaller than the value of the [`max-merge-region-size`](/pd-configuration-file.md#max-merge-region-size) (Change to 54 MiB by default since v8.4.0, automatically applied only for newly created clusters).
 
-- The number of keys in this Region is smaller than the value of [`max-merge-region-keys`](/pd-configuration-file.md#max-merge-region-keys) (Change to 540,000 by default since v8.3.0, automatically applied only for newly created clusters).
+- The number of keys in this Region is smaller than the value of [`max-merge-region-keys`](/pd-configuration-file.md#max-merge-region-keys) (Change to 540,000 by default since v8.4.0, automatically applied only for newly created clusters).
 
 ## Query scheduling status
 
diff --git a/pd-configuration-file.md b/pd-configuration-file.md
index fecdf76148e03..fbf5339bbb01e 100644
--- a/pd-configuration-file.md
+++ b/pd-configuration-file.md
@@ -261,13 +261,13 @@ Configuration items related to scheduling
 ### `max-merge-region-size`
 
 + Controls the size limit of `Region Merge`. When the Region size is greater than the specified value, PD does not merge the Region with the adjacent Regions.
-+ Default value: `54` (Before v8.3.0, the default value is `20`. Starting from v8.3.0, the default value is `54`.)
++ Default value: `54` (Before v8.4.0, the default value is `20`. Starting from v8.4.0, the default value is `54`.)
 + Unit: MiB
 
 ### `max-merge-region-keys`
 
 + Specifies the upper limit of the `Region Merge` key. When the Region key is greater than the specified value, the PD does not merge the Region with its adjacent Regions.
-+ Default value: `540000` (Before v8.3.0, the default value is `200000`. Starting from v8.3.0, the default value is `540000`.)
++ Default value: `540000` (Before v8.4.0, the default value is `200000`. Starting from v8.4.0, the default value is `540000`.)
 
 ### `patrol-region-interval`
 
diff --git a/tikv-configuration-file.md b/tikv-configuration-file.md
index 0e699f0750604..50d91c071b002 100644
--- a/tikv-configuration-file.md
+++ b/tikv-configuration-file.md
@@ -2147,7 +2147,7 @@ Configuration items related to BR backup.
 
 + The threshold of the backup SST file size. If the size of a backup file in a TiKV Region exceeds this threshold, the file is backed up to several files with the TiKV Region split into multiple Region ranges. Each of the files in the split Regions is the same size as `sst-max-size` (or slightly larger).
 + For example, when the size of a backup file in the Region of `[a,e)` is larger than `sst-max-size`, the file is backed up to several files with regions `[a,b)`, `[b,c)`, `[c,d)` and `[d,e)`, and the size of `[a,b)`, `[b,c)`, `[c,d)` is the same as that of `sst-max-size` (or slightly larger).
-+ Default value: `"384MiB"`
++ Default value: `"384MiB"`. The default value is `"144MiB"` in versions earlier than v8.4.0.
 
 ### `enable-auto-tune` <span class="version-mark">New in v5.4.0</span>