c++11 initialization T{p, ...} vs T = {p, ...} [duplicate]

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• Why does the standard differentiate between direct-list-initialization and copy-list-initialization? 1 answer

In his new book Effective Modern C++, Scott Meyers makes the statement in the section "Items 7: Distinguish between () and {} when creating objects," that:

I'll generally ignore the equals-sign-plus-braces syntax, because C++ usually treats it the same as the braces-only version.

Taking note of the "usually" qualifier, how does when and how does = { ... } differ from plain { ... }?