what is reffering this code <?xml version="1.0" ?> in system.xml and <layout version="1.0.0"> in layout custom_module.xml file ?


<?xml version="1.0" ?> defines the xml document. While there already is a newer 1.1 Version you still will mostly see the 1.0 Version: https://www.ibiblio.org/xml/books/effectivexml/chapters/03.html

the layout tag is a Magento construct and I assume that its Version is 1.0.0 since the beginning of time, but was introduced to have the possibility to upgrade the layout definition over the time.

Not the answer you're looking for? Browse other questions tagged or ask your own question.