ui:removeOne of the common things during development is to comment code in the Facelets files. But, if using the XML comment characters
<-- -->these markup will be rendered in the generated markup as a commented code, leaking some information to public that may not be noticed by developers. For avoiding these issues, you can use ui:remove nesting all those markup you want to be ignored completely.
Liferay Faces Alloy 4.1.1 + Liferay Faces Bridge Implementation 5.0.0 + Showcase Common 4.0.0 + Liferay Faces Util 3.4.1 + Mojarra 2.2.20