diff --git a/README.md b/README.md
index aa8c6aa..2eb9e09 100644
--- a/README.md
+++ b/README.md
@@ -165,4 +165,103 @@ A `location` plugin which constructs the resulting URI that the uploaded file ca
 
 ## Documentation - Plugin Development
 
-Coming soon...
+A plugin for SSHare is just a python file (`*.py`). There are currently 6 types of plugins:
+- `logger`
+- `source`
+- `name`
+- `upload`
+- `location`
+- `feedback`
+A plugin can specify be any combination of the above types. For examples of plugins see [here](src/sshare/plugins)
+and [here](https://forge.monodon.me/Gnarwhal/sshare_plugins)
+
+### General Attributes
+
+Every plugin regardless of type specifies or is provided with these attributes.
+
+#### `plugin_type`
+
+This mandatory paramater specifies what type(s) this plugin is.
+It can be either a:
+- `string` - Promotes to `{ string }`
+- `set` - A set containing each of the plugin's types. 
+
+#### `activate`
+
+This optional parameter specifies what flag(s) or argument(s) must be passed for this plugin to be activated.
+It can be either a:
+- `string` - Promotes to `{ string }`
+- `set` - Promotes to `{ plugin_type: { string, ... }, plugin_type2: { string, ... }, ... }`
+- `dict` - A dictionary that maps each type the plugin is, to the flags or arguments that activate the plugin for that type
+All arguments specified in `activate` must be provided by the user for the plugin to activate. 
+
+#### `config`
+
+This optional parameter specifies configuration options for the plugin. These values are what a user is allowed to change
+through `config.toml`. It is a map containing `{ option: default_value, ... }`. If there is no default value (i.e. it is mandatory
+that the user set it explicitly) for the option, it can be set to `NoDefault` provided by
+`from sshare.plugin.config import NoDefault`.  
+  
+While `config` is initially specified as a `dict`, when the plugin is loaded it will be converted to an object with attributes.
+For example, if a config is specified as 
+```python
+config = {
+    "example0": 42,
+}
+```
+it would then be accessed by `config.example` not `config["example"]`.
+
+#### `args`
+
+This optional parameter specifies arguments for the plugin. These values are also accessed from the `config` object,
+however they are provided via program arguments as opposed to being specified in `config.toml`. An option specified
+in both `config` and `args` will be loaded from the config file first and overriden by the program argument if
+provided. Arguments are of type `Argument` provided by `from sshare.plugin.config import Argument`.
+`Argument` takes `name` (optionally) and a list of `kwargs` equivalent to the option document [here](https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument). As a convenience there is also `Flag` provided by
+`from sshare.plugin.config import Flag`, which is for boolean arguments which take no parameters.
+`Flag` only takes a `help=...` paramater.
+
+#### `init`
+
+If a plugin needs to do any initialisation, it can be done in the `init` method. The `init` method takes no parameters
+and returns no values.
+
+#### `logger`
+
+Logger is not specified by the plugin developer, but is available inside the plugin if needed. The logger
+has three levels: `info`, `warn` and `error`.
+
+### Type Specific Attributes
+
+#### `logger`
+- `info(str)`
+- `warn(str)`
+- `error(str)`
+
+#### `source` -> `get_source()`
+
+The `get_source` function takes no arguments and returns a source. There are currently two types of sources provided by
+`from sshare.plugin.source import (Raw | File)`.
+- `Raw` - A raw data source. It has a type, a source name, and a byte array providing the data. 
+- `File` - A file or directory source. It has only the path to the file.
+
+#### `name` -> `get_name(current_name, source)`
+
+`name` plugins are chained one after the other. The first `name` plugin is provided an empty string for `current_name`.
+Each subsequent `name` plugin is provided the output of the previous `name` plugin's `get_name` function. The `source`
+parameter is the either `Raw` or `File` data source.
+
+#### `upload` -> `upload(name, source)`
+
+`upload` plugins are responsible for getting the source to the destination. 
+
+#### `location` -> `get_location(name)`
+
+The `get_location` function takes in the name of a source and returns a location that the source can now be accessed from
+(e.g. a URL).
+
+#### `feedback` -> `give_feedback(location)`
+
+The `give_feedback` function takes output from `location` plugins and presents it to the user (e.g. printing to console,
+desktop notification. etc...).
+
diff --git a/src/sshare/plugins/time.py b/src/sshare/plugins/time.py
index 53e9777..b186ca6 100644
--- a/src/sshare/plugins/time.py
+++ b/src/sshare/plugins/time.py
@@ -44,8 +44,8 @@ def _rebase(base, number):
 
 def _number_to_char(number):
     if number < 10:
-        return chr(number + 48)
+        return chr(number + 48) # 0-9
     elif number < 36:
-        return chr(number + 87)
+        return chr(number + 87) # a-z
     else:
-        return chr(number + 29)
+        return chr(number + 29) # A-Z