## # type:

One "core" field of [PMD](wiki/Plugin+Meta+Data) is the `type:` specifier in
each script:

    # type: io

It's meant to be used by common "hook" plugin systems. Albeit it can be
entirely decorational again.

  * Some apps might declare a few special values like `init` or `core`,
    and ignore all the rest.

  * Other plugin systems might utilize `sidebar` or `post-form` to tie
    scripts to specific invocation points already.

  * Or could just be a superset of [category:](wiki/category), and not
    be used any further.

Some application API and plugin needs will instead use manual per-script
code to register themselves. In which case this field would only be used
for plugin installation e.g.

Others might even combine `type:` and `category:` or additionally a custom
`class:` and `function:` field for feature lookup/invocation.


## common script types

...