In some states (e.g., TX, I believe), one must have a Professional Engineer (PE) license to advertise as an Engineer
Same thing applies in Queensland, Australia where an engineer must be, or work in association with, a Registered Professional Engineer of Queensland. More than a few hoops to jump through to get the ticket .. and, should one not have the ticket, be naughty and work as an engineer in Queensland, there is a range of sanctions which the relevant Board can initiate.
The Institution of Engineers, Australia is pushing for a similar accreditation requirement across the country. To what extent this push may be successful remains to be seen. At this stage it is expected that an engineer will hold the relevant national ticket.