Something I’ve been wondering is how to most clearly encode both a title and subtitle in an alt attribute. Does it matter how I separate “Futurama” and “Proudly

Something I’ve been wondering is how to most clearly encode both a title and subtitle in an alt attribute. Does it matter how I separate “Futurama” and “Proudly Made on Earth”? e.g. with just a space vs. semicolon, middle dot, lone hyphen, line break, etc.