Illustrative example of poor English
OK, in the French for English speakers tree I just came across this (on the iPad so can't discuss it in situ)
"Cette lettre est relative a mon pere" (this is from memory, might not be quite right - my last heart, so got bumped out) and it gave this:
"This letter is related to my father"
The problem being that this implies the letter is part of my father's family (which obviously makes no sense).
The correct translation should be "This letter relates to my father" (ie concerns/ is about) and "concerns" and "is about" really should be accepted as valid translation.
A small example, but this happens quite often and it can get a bit tiresome losing hearts to them.
I think a quick and easy way to report such errors is essential for us heavy iPad users.
Keep up the good work.
I believe you are incorrect. Dictionary.com shows the following for the verb "relate":
verb (used without object), re·lat·ed, re·lat·ing.
3 to have reference (often followed by to ).
4 to have some relation (often followed by to ).
You are not alone in your request for error reporting for iPad users, though. I see that a lot. It's a small group of people working on a very large application, though, and there's only so much they can do at a time.
"Relating" would be OK ("What is it relating to?"), and without a named party "related to" might be OK ("What is it related to?" (or "To what is it related?" for preposition pedants)) - but you will note that both of those are in the interrogative form.
In a simple statement "X is related to Y" implies either filial or causal relation, while "x relates to y" suggest it is about (has reference to) the subject, which in the context of a letter is much, much more likely.
'Is related to' can be legitimate English about something other than family members, but it is not correct in that context, nor is it commonly used in any kind of English with which I am familiar. It's just wrong. You could say 'the failure of the government to address this issue is related to low public awareness of the threat to services,' or 'the fall in revenue is related to the rise in the price of crude oil.' That would be a usage covered by your definition 3. It's a causal relationship, as I Cundell says. The father does not 'cause' the letter, though he may be the subject of the letter.