diff --git a/packages/frontend/src/os.ts b/packages/frontend/src/os.ts
index 41b4dc3c0f..716d7a0b56 100644
--- a/packages/frontend/src/os.ts
+++ b/packages/frontend/src/os.ts
@@ -153,12 +153,23 @@ export const popups = ref<{
 	events: Record<string, any>;
 }[]>([]);
 
+/**
+ * An object containing z-index values for different priority levels.
+ */
 const zIndexes = {
 	veryLow: 500000,
 	low: 1000000,
 	middle: 2000000,
 	high: 3000000,
 };
+
+/**
+ * Claims a z-index value for a given priority level.
+ * Increments the z-index value for the specified priority by 100 and returns the new value.
+ *
+ * @param {keyof typeof zIndexes} [priority='low'] - The priority level for which to claim a z-index.
+ * @returns {number} The new z-index value for the specified priority.
+ */
 export function claimZIndex(priority: keyof typeof zIndexes = 'low'): number {
 	zIndexes[priority] += 100;
 	return zIndexes[priority];