change the permissions so only root can see it, or place it else where which is what we do. All our builds have a Management folder which has subfolders for various things we can use like graphics, Documents and Deployments which is where we place the OS installer.
like this /Library/corpnamemanagement/Deployments.

You can use chflags hidden /Applications/appname.app to hide things like that. In recent OSes, it doesn't work on built-in apps (you get a "Operation not permitted" error), but might still work for Install macOS.app.

(use chflags nohidden... to make items visible again)

Hi, when I go by the blog post and try it on a test machine, it does not do anything. It has the most current High Sierra.app from the app store. When I go into Terminal it brings back an error code: 800.

Any ideas?

@niacobelli, I believe that error 800 indicates the drive may not be formatted as APFS. To verify, open Disk Utility and you'll find it's either HFS+ (not supported with this command) or APFS.

@davidacland after hiding the install macOS using chflags, we should be able to use the script right since it is being run by root? sorry, I don't have the means to test right now. Thanks Sir!

Yes, the script will still work as chflags only hides the app from the GUI. Command-line is unaffected.