1# Pending changelog entry directory
2
3This directory contains changelog entries that have not yet been merged
4to the changelog file ([`../ChangeLog`](../ChangeLog)).
5
6## What requires a changelog entry?
7
8Write a changelog entry if there is a user-visible change. This includes:
9
10* Bug fixes in the library or in sample programs: fixing a security hole,
11  fixing broken behavior, fixing the build in some configuration or on some
12  platform, etc.
13* New features in the library, new sample programs, or new platform support.
14* Changes in existing behavior. These should be rare. Changes in features
15  that are documented as experimental may or may not be announced, depending
16  on the extent of the change and how widely we expect the feature to be used.
17
18We generally don't include changelog entries for:
19
20* Documentation improvements.
21* Performance improvements, unless they are particularly significant.
22* Changes to parts of the code base that users don't interact with directly,
23  such as test code and test data.
24
25Until Mbed TLS 2.24.0, we required changelog entries in more cases.
26Looking at older changelog entries is good practice for how to write a
27changelog entry, but not for deciding whether to write one.
28
29## Changelog entry file format
30
31A changelog entry file must have the extension `*.txt` and must have the
32following format:
33
34~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
35Security
36   * Change description.
37   * Another change description.
38
39Features
40   * Yet another change description. This is a long change description that
41     spans multiple lines.
42   * Yet again another change description.
43
44~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
45
46The permitted changelog entry categories are as follows:
47<!-- Keep this synchronized with STANDARD_CATEGORIES in assemble_changelog.py! -->
48
49    API changes
50    Default behavior changes
51    Requirement changes
52    New deprecations
53    Removals
54    Features
55    Security
56    Bugfix
57    Changes
58
59Use “Changes” for anything that doesn't fit in the other categories.
60
61## How to write a changelog entry
62
63Each entry starts with three spaces, an asterisk and a space. Continuation
64lines start with 5 spaces. Lines wrap at 79 characters.
65
66Write full English sentences with proper capitalization and punctuation. Use
67the present tense. Use the imperative where applicable. For example: “Fix a
68bug in mbedtls_xxx() ….”
69
70Include GitHub issue numbers where relevant. Use the format “#1234” for an
71Mbed TLS issue. Add other external references such as CVE numbers where
72applicable.
73
74Credit bug reporters where applicable.
75
76**Explain why, not how**. Remember that the audience is the users of the
77library, not its developers. In particular, for a bug fix, explain the
78consequences of the bug, not how the bug was fixed. For a new feature, explain
79why one might be interested in the feature. For an API change or a deprecation,
80explain how to update existing applications.
81
82See [existing entries](../ChangeLog) for examples.
83
84## How `ChangeLog` is updated
85
86Run [`../scripts/assemble_changelog.py`](../scripts/assemble_changelog.py)
87from a Git working copy
88to move the entries from files in `ChangeLog.d` to the main `ChangeLog` file.
89