Remove variant label length limitation (#41)

Signed-off-by: Michał Górny <mgorny@quansight.com>
Co-authored-by: konsti <konstin@mailbox.org>

Author: mgorny

peps/pep-0825.rst

@@ -137,8 +137,8 @@ to:
 
 Variant wheels MUST include the variant label component. Conversely,
 wheels without variant label are non-variant wheels. The variant label
-MUST consist only of ``0-9``, ``a-z``, ``_`` and ``.`` ASCII characters,
-and be 1-16 characters long (``^[0-9a-z_.]{1,16}$``).
+MUST be non-empty and consist only of ``0-9``, ``a-z``, ``_`` and ``.``
+ASCII characters (``^[0-9a-z_.]+$``).
 
 Every variant label MUST uniquely correspond to a specific set of
 variant properties, which MUST be the same for all wheels using the same
@@ -841,6 +841,12 @@ commonly used today reject it:
      numpy-2.3.2-cp313-cp313t-musllinux_1_2_x86_64-x86_64_v3.whl
                  ^^^^^
 
+The addition of the variant label increases the filename length. On platforms
+with a low total path length limit such as Windows, long filenames are a
+concern. However, given that the name and version components are already
+unrestricted, we do not set a specific limit in this PEP. Others, such as PyPI,
+may set a limit for total filename length.
+
 Aside from this explicit incompatibility, the specification makes
 minimal and non-intrusive changes to the binary package format. The
 `variant metadata`_ is stored in a separate file in the ``.dist-info``
@@ -965,6 +971,7 @@ Change History
     best value that is compatible with the system, for every feature,
     rather than all compatible values, and add a fallback to ordering
     on variant label.
+  - Removed the variant label length limitation.
 
 
 Appendices