The manifest.php file in the newer plugins architecture.

PluginId
The id number assigned by the Zen Cart forum site when submitting the plugin for review. e.g. https://www.zen-cart.com/downloads.php?do=file&id=1583 This is used by the store’s Plugin Manager to check for whether new versions have been submitted.
How does one know what this number is before it has been submitted or does the first version of a plugin need to be submitted without this number? Seems chicken-and-egg like.

So, should one just leave it as 0 to start with?