diff --git a/base/src/main/kotlin/de/staropensource/engine/base/annotation/NonKotlinContact.kt b/base/src/main/kotlin/de/staropensource/engine/base/annotation/NonKotlinContact.kt
new file mode 100644
index 0000000..0472721
--- /dev/null
+++ b/base/src/main/kotlin/de/staropensource/engine/base/annotation/NonKotlinContact.kt
@@ -0,0 +1,49 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ * with an exception allowing classpath linking.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.staropensource.engine.base.annotation
+
+/**
+ * Marks contacts with classes or code in other
+ * programming languages besides Kotlin in
+ * the public API.
+ *
+ * Using anything non-Kotlin in conjunction with
+ * the StarOpenSource Engine is highly discouraged,
+ * as the engine may be multiplatform in future
+ * releases and will not support using other
+ * languages.
+ *
+ * Using anything in contact with non-Kotlin code
+ * is therefore deemed unsafe and should be
+ * avoided at all costs. Only use methods and
+ * variables interacting with non-Kotlin stuff
+ * if absolutely necessary.
+ *
+ * @since v1-alpha10
+ */
+@Target(
+    AnnotationTarget.TYPE_PARAMETER,
+    AnnotationTarget.VALUE_PARAMETER,
+    AnnotationTarget.TYPE,
+)
+@Retention(AnnotationRetention.RUNTIME)
+@MustBeDocumented
+annotation class NonKotlinContact
diff --git a/base/src/main/kotlin/de/staropensource/engine/base/annotation/package-info.kt b/base/src/main/kotlin/de/staropensource/engine/base/annotation/package-info.kt
new file mode 100644
index 0000000..493bf09
--- /dev/null
+++ b/base/src/main/kotlin/de/staropensource/engine/base/annotation/package-info.kt
@@ -0,0 +1,26 @@
+/*
+ * STAROPENSOURCE ENGINE SOURCE FILE
+ * Copyright (c) 2024 The StarOpenSource Engine Authors
+ * Licensed under the GNU Affero General Public License v3
+ * with an exception allowing classpath linking.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Annotations used by the engine and subsystems.
+ *
+ * @since v1-alpha10
+ */
+package de.staropensource.engine.base.annotation;