Please would you expand what you mean by that in this context.
Simples: My impression is that all these symbols mean pretty much the same thing and it's just on the whim of the author or development platform which they use.
I have a lot to do with elderly people (yes, even older than me... or Trev!) - some still bright as a button, others less so - and it is my thesis that the world is becoming / has become a difficult and confusing place for them, not because of modern technology
per se, but because modern technology displaces simpler technologies due to market forces. Almost nothing "just works" now without having to boot up, and potentially crash - not even a transistor radio.
I am having enormous difficulty getting one elderly friend, still fully in possession of marbles, to use an iPad, for example. The main reason for this is there are few visual cues what to do - being gesture-operated, you have to know what to do without having the reminder of a menu of options to choose from.
My thesis is that the modern world has been designed by twenty- and thirty-somethings, for twenty- and thirty-somethings, and that age group have little or no appreciation for what it is like to be 40, let alone 80. There must always be a built-in way to get "help" at any stage of operation, and that "help" must not disappear from the screen in a matter of seconds (eg TV menus). A major shift of mind-set is required, because the "movers and shakers" should be designing for their parents and grandparents, in preparation for their own old age.
Even as simple a thing as a coffee shop: is the seating accessible and comfortable? Chances are it is high and/or hard, when the elderly bum can't get up there or has little built-in padding and needs a cushion. Are the cups accessible? Chances are they are huge and too heavy for weakening muscles, and even if small/light enough have a finger grip so small you're lucky if you can get one finger through it let alone three, and relies on strength of grip. These coffee shops don't intend to exclude people, but they are because their designers do not understand.
However, back on topic, another "aid" to comprehension is to limit the number of different symbols one is supposed to know! Does it really matter whether a particular icon means specifically a continuation or a sub-menu? They both do the same thing in effect (some more options appear, somehow), and could be represented by the same icon.