This screen is used to create/view/edit the Tax Type lookups. These set the available taxes on the Taxes tabs for Practices, Practice Locations, Product Types, Products, and Customers.

The fields are as follows:

Name - the tax name (normally its short name such as GST or VAT)
Description - the full name of the tax
Percentage - the tax rate as a percentage
Active - uncheck the box to deactive the tax type
Tax Scheme - can be set to None, Goods and services tax, or Value added tax.
Tax Category - can be set to None, Standard rated, or Zero rated.

The latter two fields (Tax Scheme and Category) are used only are used to map ESCI (e-Supply Chain Interface) taxes to their OpenVPMS equivalents.  See the ESCI documentation for more details: http://www.openvpms.org/documentation/esci  If you are not using ESCI, then these two can be left at their defaults, ie None.