Leaving out optional tags makes sense. These days, at least with web-apps, It's not like we are writing a <head> for every page. It's just a partial you rarely ever interact with anyway. Either leave them in or take them out. The only negative I could see is that some people may not know what's optional–think you're a dummy–and put them back in. Probably best to just follow the conventions of whatever framework you use. Save your fighting energy for trailing commas in JSON! :)