☐ Ignore Case will make the various keywords ignore case while matching.

Dock or Undock will toggle whether the UDL dialog is a standalone dialog, or docked in the Notepad++ window.

Export… will save a UDL XML file to a location of your choosing you can then share this with others, so that they can import your UDL for their own use.

Import… will import a UDL XML file into your current instance ( see below).

Save As will copy the currently-selected UDL, with all its stylings and rules, to a new name.

Create New will copy the default User Defined Language stylings and rules to a new name.

There is a special entry for the default UDL, called User Defined Language here (though it shows up in the Notepad++ Languages menu as User-Defined), which can be used as a template for other UDL.

User Language pulldown lists all the existing UDL will allow you to select the UDL you would like to edit or examine.

The main pulldowns and buttons are available, whichever configuration tab is active: Using Languages > Define Your Language… will bring up a dialog box (which can be docked as a pane in the Notepad++ Window, or can be a floating dialog box).

The Languages menu on the menu-bar includes the list of built-in languages, and below those are a separator followed by Define Your Language… and a list of any UDL that have been already defined. Enter the User Defined Languages (or “UDL” for short): the UDL interface allows the user to define rules for formatting normal text, keywords, comments, numbers to define delimiters (like quotes around strings or parentheses around lists) which will cause text between those delimiters to be formatted and to define symbols or keywords that can be used to allow folding (on-demand hiding and unhiding of blocks of code or text).

However, not every possible language or formatting style is available. Notepad++ comes prepackaged with many Language lexers, which apply syntax highlighting to source code or textual data.

User Defined Languages What are User Defined Languages

How to format xml in notepad++