インテル® Fortran コンパイラー 19.0 デベロッパー・ガイドおよびリファレンス
A constant expression is an expression that is evaluated when a program is compiled. It can be used as a kind type parameter, a named constant, or to specify an initial value for an entity.
A specification expression is a scalar, integer expression that is restricted specifications such as length type parameters and array bounds.
Constant and specification expressions can appear in specification statements, with some restrictions.