diff --git a/model/Build/Classes/Build.md b/model/Build/Classes/Build.md
index 6448a1117..e2e22e69f 100644
--- a/model/Build/Classes/Build.md
+++ b/model/Build/Classes/Build.md
@@ -16,6 +16,8 @@ those defined in [SLSA provenance](https://slsa.dev/provenance/v0.2).
 
 ExternalIdentifier of type "urlScheme" may be used to identify build logs. In this case, the comment of the ExternalIdentifier should be "LogReference".
 
+Note that buildStart and buildEnd are optional, and may be omitted to simplify creating reproducible builds.
+
 ## Metadata
 
 - name: Build
diff --git a/model/Core/Classes/CreationInfo.md b/model/Core/Classes/CreationInfo.md
index 69995f16d..77353abcb 100644
--- a/model/Core/Classes/CreationInfo.md
+++ b/model/Core/Classes/CreationInfo.md
@@ -10,6 +10,8 @@ Provides information about the creation of the Element.
 
 The CreationInfo provides information about who created the Element, and when and how it was created. 
 
+The dateTime created is often the date of last change (e.g., a git commit date), not the date when the SPDX data was created, as doing so supports reproducible builds.
+
 ## Metadata
 
 - name: CreationInfo
diff --git a/model/Core/Properties/created.md b/model/Core/Properties/created.md
index 1aad2f75f..fe02af3ed 100644
--- a/model/Core/Properties/created.md
+++ b/model/Core/Properties/created.md
@@ -9,7 +9,7 @@ Identifies when the Element was originally created.
 ## Description
 
 Created is a date that identifies when the Element was originally created.
-The time stamp can serve as an indication as to whether the analysis needs to be updated.
+The time stamp can serve as an indication as to whether the analysis needs to be updated. This is often the date of last change (e.g., a git commit date), not the date when the SPDX data was created, as doing so supports reproducible builds.
 
 ## Metadata