Clarify that direct-initialized, copy-initialized from E

Presumably, "direct-initialized from E" and "copy-initialized from E" should be distinguishable with direct-initialization and copy-initialization. The initialization might be considered as an expression, as per

If a language construct is defined to produce an implicit call of a function, a use of the language construct is considered to be an expression for the purposes of this definition. Conversions applied to the result of an expression in order to satisfy the requirements of the language construct in which the expression appears are also considered to be part of the full-expression. For an initializer, performing the initialization of the entity (including evaluating default member initializers of an aggregate) is also considered part of the full-expression.

I mean that an initialization has been a recipe(comprises the function will be called, if any) whose evaluation will initialize the destination object. However, direct(copy)-initialized from E might be a bit different.

There are many such a usage in the standard, such as
expr.static.cast#4

Otherwise, the result object is direct-initialized from E

dcl.dcl#dcl.init.aggr-5

Otherwise, if the element is not a reference, the element is copy-initialized from an empty initializer list

So, what's the appearance of form here for copy-initialize or direct-initialize respectively? In other words, if we say that an entity t is direct-initialized from an expression E, what's the form?

T t(E); // #1
T t{E}; //#2

Does it refer to #1 or #2? Similarly, when we say that an entity t is copy-initialized from an expression E, what's the form?

T t = E; //#3
T t = {E};  //#4

It does not specify in the standard.

Start by reading the cited [expr.static.cast#4] and [dcl.dcl#dcl.init.aggr-5] clauses, then compare the direct- and copy-initialization forms shown in the issue. Clarify whether the standard's phrases identify a particular syntactic form or describe an initialization operation, and update the relevant wording once the distinction is resolved.