What is the vocative expression we can use to attract the attention of someone whose name or surname we don't know?

I was reading one of my old English Language books when I came across this:

"Madame, Señora, Signora, etc, are foreign vocative expressions and they have no equivalent, in either British or American English, for everyday use, among equals. Madam is a vocative expression used only by people in a position of permanent or temporary service; e.g. servants, waiters, waitresses, hairdressers, shop-keepers and assistants, clerks, etc. Outside such service no vocative expression exists; that is to say, if one does not know the surname of a person, in front of which one can put the Mrs. or Miss, etc, there is absolutely nothing one can use. You may ask: "But what happens if a lady drops something in the street and I pick it up and want to attract her attention? How can I call her?" The answer is that you cannot call her - unless you know her name. If you want to give her whatever she has dropped, you must overtake her and hand it to her without any vocative expression at all. In England, the same thing applies to the use of Sir; it is used only as an expression of service or respect (e.g. subordinates to superiors, school-children to their masters, young people to very much older people); i.e. among equals, there is no word to use. In America, however, men - but not women - do often use Sir among equals.

This textbook was printed in 1961. ("British and American English" by John Millington Ward, pg 51-52, Longmans, Green and Co Ltd, 1961.) My question is: dumb as it may seem, was this what people did at that time ? (Overtake someone who dropped something without calling him) Is it still what people are expected to do in America and England in 2014 ?

That sounds ridiculous to me. I doubt if this was even true in 1961. It sounds like a complete misunderstanding of the rules of addressing nobility in the UK.

The way you address someone in that situation is highly regional- and dialect-specific and depends on who is doing the addressing and whom they are addressing.

"Ma'am" and "Sir" are currently common in the US and will never get you in trouble.

In the UK you would commonly just say "excuse me" or "pardon me" rather than use a vocative especially among equals (or maybe "Oi!" in working-class neighborhoods). You certainly aren't expected to run around in front of someone just because there's no word to use.

You'll also hear everything from "miss", "gov'nor", "chief", "mister," "buddy", "young man" or "young lady," "mate," "pal," etc. etc. depending on region, dialect, ethnic group, etc.

'Excuse me!' said loudly will usually get a stranger's attention

Depending on socio-economic context, in Britain you could, if you were in the Old Kent Road or Whitechapel, say 'Oi, mate/darlin', you just dropped somefink'. If you were in Park Lane or Mayfair you would say 'Excuse me Madame/Sir, something fell from your attire' (well perhaps not the last five words - but you get my point).

I would have no difficulty saying 'Excuse me, you have just dropped something'.