diff --git a/android/sdk.go b/android/sdk.go
index a9cc547..42f95b7 100644
--- a/android/sdk.go
+++ b/android/sdk.go
@@ -735,8 +735,8 @@
 	//   have common values. Those fields are cleared and the common value added to the common
 	//   properties.
 	//
-	//   A field annotated with a tag of `sdk:"keep"` will be treated as if it
-	//   was not capitalized, i.e. not optimized for common values.
+	//   A field annotated with a tag of `sdk:"ignore"` will be treated as if it
+	//   was not capitalized, i.e. ignored and not optimized for common values.
 	//
 	//   A field annotated with a tag of `android:"arch_variant"` will be allowed to have
 	//   values that differ by arch, fields not tagged as such must have common values across
@@ -923,18 +923,18 @@
 	// the locations of any of their prebuilt files in the snapshot by os type to prevent them
 	// from colliding. See OsPrefix().
 	//
-	// This property is the same for all variants of a member and so would be optimized away
-	// if it was not explicitly kept.
-	Os_count int `sdk:"keep"`
+	// Ignore this property during optimization. This is needed because this property is the same for
+	// all variants of a member and so would be optimized away if it was not ignored.
+	Os_count int `sdk:"ignore"`
 
 	// The os type for which these properties refer.
 	//
 	// Provided to allow a member to differentiate between os types in the locations of their
 	// prebuilt files when it supports more than one os type.
 	//
-	// This property is the same for all os type specific variants of a member and so would be
-	// optimized away if it was not explicitly kept.
-	Os OsType `sdk:"keep"`
+	// Ignore this property during optimization. This is needed because this property is the same for
+	// all variants of a member and so would be optimized away if it was not ignored.
+	Os OsType `sdk:"ignore"`
 
 	// The setting to use for the compile_multilib property.
 	Compile_multilib string `android:"arch_variant"`
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
index 8b8e1d7..4be1e79 100644
--- a/sdk/sdk_test.go
+++ b/sdk/sdk_test.go
@@ -218,15 +218,15 @@
 }
 
 type testPropertiesStruct struct {
-	name        string
-	private     string
-	Public_Kept string `sdk:"keep"`
-	S_Common    string
-	S_Different string `android:"arch_variant"`
-	A_Common    []string
-	A_Different []string `android:"arch_variant"`
-	F_Common    *bool
-	F_Different *bool `android:"arch_variant"`
+	name          string
+	private       string
+	Public_Ignore string `sdk:"ignore"`
+	S_Common      string
+	S_Different   string `android:"arch_variant"`
+	A_Common      []string
+	A_Different   []string `android:"arch_variant"`
+	F_Common      *bool
+	F_Different   *bool `android:"arch_variant"`
 	EmbeddedPropertiesStruct
 }
 
@@ -244,30 +244,30 @@
 	common := &testPropertiesStruct{name: "common"}
 	structs := []propertiesContainer{
 		&testPropertiesStruct{
-			name:        "struct-0",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "common",
-			S_Different: "upper",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string{"alpha", "beta"},
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: proptools.BoolPtr(false),
+			name:          "struct-0",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "common",
+			S_Different:   "upper",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string{"alpha", "beta"},
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   proptools.BoolPtr(false),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "embedded_upper",
 			},
 		},
 		&testPropertiesStruct{
-			name:        "struct-1",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "common",
-			S_Different: "lower",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string{"alpha", "delta"},
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: proptools.BoolPtr(true),
+			name:          "struct-1",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "common",
+			S_Different:   "lower",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string{"alpha", "delta"},
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   proptools.BoolPtr(true),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "embedded_lower",
@@ -282,15 +282,15 @@
 
 	android.AssertDeepEquals(t, "common properties not correct",
 		&testPropertiesStruct{
-			name:        "common",
-			private:     "",
-			Public_Kept: "",
-			S_Common:    "common",
-			S_Different: "",
-			A_Common:    []string{"first", "second"},
-			A_Different: []string(nil),
-			F_Common:    proptools.BoolPtr(false),
-			F_Different: nil,
+			name:          "common",
+			private:       "",
+			Public_Ignore: "",
+			S_Common:      "common",
+			S_Different:   "",
+			A_Common:      []string{"first", "second"},
+			A_Different:   []string(nil),
+			F_Common:      proptools.BoolPtr(false),
+			F_Different:   nil,
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "embedded_common",
 				S_Embedded_Different: "",
@@ -300,15 +300,15 @@
 
 	android.AssertDeepEquals(t, "updated properties[0] not correct",
 		&testPropertiesStruct{
-			name:        "struct-0",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "",
-			S_Different: "upper",
-			A_Common:    nil,
-			A_Different: []string{"alpha", "beta"},
-			F_Common:    nil,
-			F_Different: proptools.BoolPtr(false),
+			name:          "struct-0",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "",
+			S_Different:   "upper",
+			A_Common:      nil,
+			A_Different:   []string{"alpha", "beta"},
+			F_Common:      nil,
+			F_Different:   proptools.BoolPtr(false),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "",
 				S_Embedded_Different: "embedded_upper",
@@ -318,15 +318,15 @@
 
 	android.AssertDeepEquals(t, "updated properties[1] not correct",
 		&testPropertiesStruct{
-			name:        "struct-1",
-			private:     "common",
-			Public_Kept: "common",
-			S_Common:    "",
-			S_Different: "lower",
-			A_Common:    nil,
-			A_Different: []string{"alpha", "delta"},
-			F_Common:    nil,
-			F_Different: proptools.BoolPtr(true),
+			name:          "struct-1",
+			private:       "common",
+			Public_Ignore: "common",
+			S_Common:      "",
+			S_Different:   "lower",
+			A_Common:      nil,
+			A_Different:   []string{"alpha", "delta"},
+			F_Common:      nil,
+			F_Different:   proptools.BoolPtr(true),
 			EmbeddedPropertiesStruct: EmbeddedPropertiesStruct{
 				S_Embedded_Common:    "",
 				S_Embedded_Different: "embedded_lower",
diff --git a/sdk/update.go b/sdk/update.go
index 81f3672..f20f1d6 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -2217,8 +2217,8 @@
 			continue
 		}
 
-		// Ignore fields whose value should be kept.
-		if proptools.HasTag(field, "sdk", "keep") {
+		// Ignore fields tagged with sdk:"ignore".
+		if proptools.HasTag(field, "sdk", "ignore") {
 			continue
 		}