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+# Contributing to Datetime Extras
+
+This module aims to be a set of widgets, formatters, and other tools to extend
+the core Datetime and Datetime Range modules. It serves as both a staging ground
+to get new features into core, and also as a place to centrally collect and
+maintain features that should live in contrib.
+
+While existing as a contrib module, this code SHOULD follow Drupal best
+practices, such as:
+- [coding standards](https://www.drupal.org/docs/develop/standards)
+- [test coverage](https://www.drupal.org/docs/8/testing)
+For code to be included in core, features MUST follow these practices.
+
+## Naming Conventions
+
+### Field plugin IDs
+
+```{field-type}_{feature-name}```
+
+Every field-related plugin in here will operate on a specific field
+type. Generally either ```datetime``` or ```daterange```. That MUST be the first
+part of the plugin ID.
+
+Since the plugins already know what kind of thing they are (widget, formatter,
+etc) via namespace and otherwise, we don't want that also in the ID.
+
+The ```_{feature-name}``` part tells you what feature is provided by that plugin
+and guarantees uniqueness. If the feature wants multiple words, separate with
+more underscores.
+
+For example:
+
+ - ```daterange_duration```
+ - ```daterange_compact```
+ - ```datetime_configurable_list```
+
+### Other plugin IDs
+
+TBD
+
+None yet, but maybe we'll start adding other things (blocks, etc).
+
+### Config IDs
+
+MUST start with ```datetime_extras.``` (including the period).
+
+Otherwise, attempt to match the ```_{feature-name}``` part of the ID from any
+related plugins.
+
+### Class names
+
+Plugin classes MUST follow the agreed upon plugin ID format, plus existing core
+conventions.
+
+Examples:
+
+```daterange_duration``` => ```DateRangeDurationWidget```
+```daterange_compact``` => ```DateRangeCompactFormatter```
+```datetime_configurable_list``` => ```DateTimeConfigurableListWidget```
+
+### Services
+
+Service IDs MUST have at least:
+
+```datetime_extras.{service-name}```
+
+Service IDs SHOULD have the form:
+
+```datetime_extras.{feature-name}.{service-name}```
+
+Example ID: ```datetime_extras.daterange_compact.formatter```
+Example class: ```Drupal\datetime_extras\DateRangeCompactFormatter```
+
+***
+
+Last Modified: 2019/02/09