diff --git a/rules/aep0004/aep0004.go b/rules/aep0004/aep0004.go
index ab75ecfd..32cc57e3 100644
--- a/rules/aep0004/aep0004.go
+++ b/rules/aep0004/aep0004.go
@@ -91,7 +91,7 @@ func getDesiredPattern(pattern string) string {
 	for _, token := range strings.Split(pattern, "/") {
 		if strings.HasPrefix(token, "{") && strings.HasSuffix(token, "}") {
 			varname := token[1 : len(token)-1]
-			want = append(want, fmt.Sprintf("{%s}", strings.TrimSuffix(strcase.SnakeCase(varname), "_id")))
+			want = append(want, fmt.Sprintf("{%s}", strcase.SnakeCase(varname)))
 		} else {
 			want = append(want, strcase.LowerCamelCase(token))
 		}
diff --git a/rules/aep0004/resource_definition_variables_test.go b/rules/aep0004/resource_definition_variables_test.go
index 5e76680f..6b12ffb0 100644
--- a/rules/aep0004/resource_definition_variables_test.go
+++ b/rules/aep0004/resource_definition_variables_test.go
@@ -27,12 +27,10 @@ func TestResourceDefinitionVariables(t *testing.T) {
 		problems testutils.Problems
 	}{
 		{"Valid", "publishers/{publisher}/electronicBooks/{electronic_book}", testutils.Problems{}},
+		{"ValidWithIdSuffix", "publishers/{publisher_id}/electronicBooks/{electronic_book_id}", testutils.Problems{}},
 		{"CamelCase", "publishers/{publisher}/electronicBooks/{electronicBook}", testutils.Problems{{
 			Message: "publishers/{publisher}/electronicBooks/{electronic_book}",
 		}}},
-		{"ID", "publishers/{publisher}/electronicBooks/{electronic_book_id}", testutils.Problems{{
-			Message: "publishers/{publisher}/electronicBooks/{electronic_book}",
-		}}},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			f := testutils.ParseProto3Tmpl(t, `
diff --git a/rules/aep0004/resource_name_components_alternate.go b/rules/aep0004/resource_name_components_alternate.go
index 8dfb1228..7e205ff8 100644
--- a/rules/aep0004/resource_name_components_alternate.go
+++ b/rules/aep0004/resource_name_components_alternate.go
@@ -25,7 +25,7 @@ import (
 	"github.com/jhump/protoreflect/desc"
 )
 
-var identifierRegexp = regexp.MustCompile("^{[a-z][-a-z0-9]*[a-z0-9]}$")
+var identifierRegexp = regexp.MustCompile("^{[a-z][_a-z0-9-]*[a-z0-9]}$")
 
 var resourceNameComponentsAlternate = &lint.MessageRule{
 	Name:     lint.NewRuleName(4, "resource-name-components-alternate"),
diff --git a/rules/aep0004/resource_name_components_alternate_test.go b/rules/aep0004/resource_name_components_alternate_test.go
index e2c3e83f..55866311 100644
--- a/rules/aep0004/resource_name_components_alternate_test.go
+++ b/rules/aep0004/resource_name_components_alternate_test.go
@@ -29,6 +29,7 @@ func TestResourceNameComponentsAlternate(t *testing.T) {
 		{"Valid", "author/{author}/books/{book}", testutils.Problems{}},
 		{"Valid", "publishers/{publisher}/books/{book}/editions/{book-edition}", testutils.Problems{}},
 		{"ValidSingleton", "user/{user}/config", testutils.Problems{}},
+		{"ValidWithIdSuffix", "stores/{store_id}/items/{item_id}", testutils.Problems{}},
 		{"InvalidDoubleCollection", "author/books/{book}", testutils.Problems{{Message: "must alternate"}}},
 		{"InvalidDoubleIdentifier", "books/{author}/{book}", testutils.Problems{{Message: "must alternate"}}},
 	} {
diff --git a/rules/aep0004/resource_variables.go b/rules/aep0004/resource_variables.go
index bc64537e..2af7f244 100644
--- a/rules/aep0004/resource_variables.go
+++ b/rules/aep0004/resource_variables.go
@@ -54,16 +54,6 @@ func lintResourceVariables(resource *annotations.ResourceDescriptor, desc desc.D
 					Location:   loc,
 				}}
 			}
-			if strings.HasSuffix(variable, "_id") {
-				return []lint.Problem{{
-					Message: fmt.Sprintf(
-						"Variable names should omit the `_id` suffix, such as %q.",
-						getDesiredPattern(pattern),
-					),
-					Descriptor: desc,
-					Location:   loc,
-				}}
-			}
 		}
 	}
 	return nil
diff --git a/rules/aep0004/resource_variables_test.go b/rules/aep0004/resource_variables_test.go
index 383d88c8..87f0e83a 100644
--- a/rules/aep0004/resource_variables_test.go
+++ b/rules/aep0004/resource_variables_test.go
@@ -27,12 +27,10 @@ func TestResourceVariables(t *testing.T) {
 		problems testutils.Problems
 	}{
 		{"Valid", "publishers/{publisher}/electronicBooks/{electronic_book}", testutils.Problems{}},
+		{"ValidWithIdSuffix", "publishers/{publisher_id}/electronicBooks/{electronic_book_id}", testutils.Problems{}},
 		{"CamelCase", "publishers/{publisher}/electronicBooks/{electronicBook}", testutils.Problems{{
 			Message: "publishers/{publisher}/electronicBooks/{electronic_book}",
 		}}},
-		{"ID", "publishers/{publisher}/electronicBooks/{electronic_book_id}", testutils.Problems{{
-			Message: "publishers/{publisher}/electronicBooks/{electronic_book}",
-		}}},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			f := testutils.ParseProto3Tmpl(t, `
diff --git a/rules/aep0122/resource_collection_identifiers.go b/rules/aep0122/resource_collection_identifiers.go
index 28134cb2..0e52b429 100644
--- a/rules/aep0122/resource_collection_identifiers.go
+++ b/rules/aep0122/resource_collection_identifiers.go
@@ -45,6 +45,18 @@ var resourceCollectionIdentifiers = &lint.MessageRule{
 
 			segs := strings.Split(p, "/")
 			for _, seg := range segs {
+				if strings.HasPrefix(seg, "{") && strings.HasSuffix(seg, "}") {
+					// Variable segments can contain underscores, but must be lowercase
+					varName := seg[1 : len(seg)-1] // Remove { and }
+					if HasUpper(varName) {
+						problems = append(problems, lint.Problem{
+							Message:    "Resource pattern variables must be lowercase.",
+							Descriptor: m,
+							Location:   locations.MessageResource(m),
+						})
+					}
+					continue
+				}
 				if HasUpper(seg) || strings.Contains(seg, "_") {
 					problems = append(problems, lint.Problem{
 						Message:    "Resource patterns must use kebab-case for collection identifiers.",
diff --git a/rules/aep0122/resource_collection_identifiers_test.go b/rules/aep0122/resource_collection_identifiers_test.go
index ab24f8f0..dfb70af9 100644
--- a/rules/aep0122/resource_collection_identifiers_test.go
+++ b/rules/aep0122/resource_collection_identifiers_test.go
@@ -27,6 +27,8 @@ func TestResourceCollectionIdentifiers(t *testing.T) {
 		problems testutils.Problems
 	}{
 		{"Valid", "author/{author}/books/{book}", testutils.Problems{}},
+		{"ValidWithIdSuffix", "stores/{store_id}/items/{item_id}", testutils.Problems{}},
+		{"InvalidCapitalIdSuffix", "stores/{Store_id}/items/{item_id}", testutils.Problems{{Message: "lowercase"}}},
 		{"InvalidUpperCase", "author/{author}/Books/{book}", testutils.Problems{{Message: "kebab-case"}}},
 		{"InvalidStartsWithSlash", "/author/{author}/Books/{book}", testutils.Problems{{Message: "lowercase letter"}}},
 		{"InvalidStartsWithCapitalLetter", "Author/{author}/Books/{book}", testutils.Problems{{Message: "lowercase letter"}}},