> This idiom is not used anywhere in jQuery source

[callbacks.js](https://github.com/orkel/jquery/blob/5851c39d33a383ded559d3a0f49d87360e23421e/src/callbacks.js#L93-L105)
[intro.js](https://github.com/orkel/jquery/blob/5851c39d33a383ded559d3a0f49d87360e23421e/src/intro.js#L14) & [outro.js](https://github.com/orkel/jquery/blob/5851c39d33a383ded559d3a0f49d87360e23421e/src/outro.js)

> are you fear someone would think that's not an immediately invoked function?

Yes, precisely.