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src/api/compile-time-flags.md

@@ -4,6 +4,10 @@ outline: deep
 
 # Compile-Time Flags {#compile-time-flags}
 
+:::tip
+Compile-time flags only apply when using the `esm-bundler` build of Vue (i.e. `vue/dist/vue.esm-bundler.js`).
+:::
+
 When using Vue with a build step, it is possible to configure a number of compile-time flags to enable / disable certain features. The benefit of using compile-time flags is that features disabled this way can be removed from the final bundle via tree-shaking.
 
 Vue will work even if these flags are not explicitly configured. However, it is recommended to always configure them so that the relevant features can be properly removed when possible.