diff --git a/core/sysprop.mk b/core/sysprop.mk
index cf4b1f6..8877743 100644
--- a/core/sysprop.mk
+++ b/core/sysprop.mk
@@ -66,9 +66,12 @@
     )\
     echo "ro.$(1).build.date=`$(DATE_FROM_FILE)`" >> $(2);\
     echo "ro.$(1).build.date.utc=`$(DATE_FROM_FILE) +%s`" >> $(2);\
-    echo "ro.$(1).build.fingerprint=$(BUILD_FINGERPRINT_FROM_FILE)" >> $(2);\
-    echo "ro.$(1).build.id=$(BUILD_ID)" >> $(2);\
-    echo "ro.$(1).build.tags=$(BUILD_VERSION_TAGS)" >> $(2);\
+    # Allow optional assignments for ARC forward-declarations (b/249168657)
+    # TODO: Remove any tag-related inconsistencies once the goals from
+    # go/arc-android-sigprop-changes have been achieved.
+    echo "ro.$(1).build.fingerprint?=$(BUILD_FINGERPRINT_FROM_FILE)" >> $(2);\
+    echo "ro.$(1).build.id?=$(BUILD_ID)" >> $(2);\
+    echo "ro.$(1).build.tags?=$(BUILD_VERSION_TAGS)" >> $(2);\
     echo "ro.$(1).build.type=$(TARGET_BUILD_VARIANT)" >> $(2);\
     echo "ro.$(1).build.version.incremental=$(BUILD_NUMBER_FROM_FILE)" >> $(2);\
     echo "ro.$(1).build.version.release=$(PLATFORM_VERSION_LAST_STABLE)" >> $(2);\
@@ -565,4 +568,4 @@
 # $1 installed file path, e.g. out/target/product/vsoc_x86_64/system/build.prop
 define is-build-prop
 $(if $(findstring $1,$(ALL_INSTALLED_BUILD_PROP_FILES)),Y)
-endef
\ No newline at end of file
+endef
diff --git a/tools/buildinfo.sh b/tools/buildinfo.sh
index c2e36df..0ed9453 100755
--- a/tools/buildinfo.sh
+++ b/tools/buildinfo.sh
@@ -7,9 +7,9 @@
 if [ "$BOARD_USE_VBMETA_DIGTEST_IN_FINGERPRINT" = "true" ] ; then
   echo "ro.build.legacy.id=$BUILD_ID"
 else
-  echo "ro.build.id=$BUILD_ID"
+  echo "ro.build.id?=$BUILD_ID"
 fi
-echo "ro.build.display.id=$BUILD_DISPLAY_ID"
+echo "ro.build.display.id?=$BUILD_DISPLAY_ID"
 echo "ro.build.version.incremental=$BUILD_NUMBER"
 echo "ro.build.version.sdk=$PLATFORM_SDK_VERSION"
 echo "ro.build.version.preview_sdk=$PLATFORM_PREVIEW_SDK_VERSION"
@@ -28,7 +28,9 @@
 echo "ro.build.type=$TARGET_BUILD_TYPE"
 echo "ro.build.user=$BUILD_USERNAME"
 echo "ro.build.host=$BUILD_HOSTNAME"
-echo "ro.build.tags=$BUILD_VERSION_TAGS"
+# TODO: Remove any tag-related optional property declarations once the goals
+# from go/arc-android-sigprop-changes have been achieved.
+echo "ro.build.tags?=$BUILD_VERSION_TAGS"
 echo "ro.build.flavor=$TARGET_BUILD_FLAVOR"
 
 # These values are deprecated, use "ro.product.cpu.abilist"
@@ -49,7 +51,7 @@
 echo "ro.build.product=$TARGET_DEVICE"
 
 echo "# Do not try to parse description or thumbprint"
-echo "ro.build.description=$PRIVATE_BUILD_DESC"
+echo "ro.build.description?=$PRIVATE_BUILD_DESC"
 if [ -n "$BUILD_THUMBPRINT" ] ; then
   echo "ro.build.thumbprint=$BUILD_THUMBPRINT"
 fi