"Essere" with a profession

Question

My Italian textbook says that we can use essere with a profession sticking to the following rules: If essere is followed by a noun only (no adjective), you don't use any article, e.g.

Lui è dottore.

If essere is followed by a noun and an adjective, you use an indefinite article, e.g.

Lui è un buon dottore.

I saw a YouTube video where native Italians talk about their jobs. One of them says:

Sono giornalista.

Another says:

Sono un sacerdote.

It's obvious that you can include or exclude an indefinite article in an Italian phrase stating your profession with essere without an adjective.

My question is this: is any of them more correct than the other or are both equally correct?

Answer 1

The difference is minimal: “Sono un ingegnere" literally means "I'm an engineer" while “Sono ingegnere" could perhaps be intended as "My profession is engineer". However, both forms are usually used in identical contexts and both are grammatically correct. The form "Sono un ingegnere" is widely used.