Allow empty values in the spec

conf.py

@@ -18,11 +18,11 @@
 # -- Project information -----------------------------------------------------
 
 project = 'EditorConfig Specification'
-copyright = '2019--2020, EditorConfig Team'
+copyright = '2019--2024, EditorConfig Team'
 author = 'EditorConfig Team'
 
-version = '0.16.0'
-release = '0.16.0'
+version = '0.17.0'
+release = '0.17.0'
 
 # -- General configuration ---------------------------------------------------
 

index.rst

@@ -73,24 +73,28 @@ EditorConfig organization.
 File Format
 ===========
 
+.. versionchanged:: 0.17.0
+
 EditorConfig files are in an INI-like file format.
-In an EditorConfig file, all beginning whitespace on each line is considered
-irrelevant. Each line must be one of the following:
+In an EditorConfig file, all beginning whitespace on each line is ignored.
+Each line must be one of the following, once leading whitespace is removed
+(and ignoring any trailing line separator):
 
-- Blank: contains only whitespace characters.
+- Blank: contains nothing.
 - Comment: starts with a ``;`` or a ``#``.
 - Section Header: starts with a ``[`` and ends with a ``]``.
- - May not use any non-whitespace characters outside of the surrounding
- brackets.
+ - Trailing whitespace may follow the closing ``]``.
  - May contain any characters between the square brackets (e.g.,
  ``[`` and ``]`` and even spaces and tabs are allowed).
  - Forward slashes (``/``) are used as path separators.
  - Backslashes (``\\``) are not allowed as path separators (even on Windows).
-- Key-Value Pair (or Pair): contains a key and a value, separated by an `=`.
- - Key: The part before the first `=` (trimmed of whitespace, but including
- any whitespace in the middle).
- - Value: The part after the first `=` (trimmed of whitespace, but including
- any whitespace in the middle).
+- Key-Value Pair (or Pair): contains a key, an ``=``, and optionally a value.
+ - Key: The part before the first ``=`` on the line.
+ - Value: The part after the first ``=`` on the line.
+ - Keys and values are trimmed of leading and trailing whitespace, but
+ include any whitespace that is between non-whitespace characters.
+ - If there is nothing, or only whitespace, after the first ``=`` on the line,
+ then the value is an empty string (i.e., ``""`` in C or Python).
 
 Any line that is not one of the above is invalid.
 
@@ -115,7 +119,7 @@ This specification does not define any "escaping" mechanism for
 
 .. admonition :: Compatibility
 
- The EditorConfig file format formerly allowed the use of `;` and `#` after the
+ The EditorConfig file format formerly allowed the use of ``;`` and ``;`` after the
  beginning of the line to mark the rest of a line as comment. This led to
  confusion how to parse values containing those characters. Old EditorConfig
  parsers may still allow inline comments.