# Portable way to check existence of ISO\_FORTRAN\_ENV intrinsic module **URL:** \ **Category:** Help\ **Created:** [October 29, 2021, 7:51pm UTC](https://fortran-lang.discourse.group/t/portable-way-to-check-existence-of-iso-fortran-env-intrinsic-module/2193 "2021-10-29T19:51:02Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![milancurcic](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/milancurcic/32/2_2.png) [@milancurcic](https://fortran-lang.discourse.group/u/milancurcic)\ **Post date:** [October 31, 2021, 5:00pm UTC](https://fortran-lang.discourse.group/t/portable-way-to-check-existence-of-iso-fortran-env-intrinsic-module/2193/9 "2021-10-31T17:00:46Z")
> [@wyphan](#): > > Interesting. I thought `DOUBLE PRECISION` got deprecated in one of the newer standards? At least that’s what MFE says – it’s placed in Appendix A, “Deprecated features”. @msz59 explained well the nuance between the type name and the double precision real kind. In your post I see one more instance of confusion that I also had until recently–the meaning of MFE’s _deprecated_. The standard defines _obsolescent_ (considered redundant and subject to deletion in the future) and _deleted_ features. It doesn’t define _deprecated_ features. MFE defines deprecated features and this “status” is the authors’ choice and unrelated to the the standard. Quoting from A.1: > We note that his decision to group certain features into an appendix and to deprecate their use is ours alone, and does not have the actual or implied approval of either WG5 or J3. The thread where I asked about this is: > [@What is the status of the sequence attribute and statement?](https://fortran-lang.discourse.group/t/what-is-the-status-of-the-sequence-attribute-and-statement/720): > > Modern Fortran Explained: Incorporating Fortran 2018 lists in A.2 storage association, including sequence attribute, statement, and type as deprecated features. The Authors define a deprecated feature as a feature that became redundant (for sequence, specifically, since Fortran 95) and whose use is not recommended. They say that deprecated feature have potential to be marked as obsolescent by the Standard, which in turn, opens a path toward deletion. The [Standard](https://j3-fortran.org/doc/year/18/18-007r1.pdf), however, doesn’t say anything… --- _[View the full topic](https://fortran-lang.discourse.group/t/portable-way-to-check-existence-of-iso-fortran-env-intrinsic-module/2193)._