@import ../template.nml
%<make_doc({"Styles"}, "User-Defined", "User-Defined Styles")>%

# Defining a custom style
```Lua
function undercustom_start(color)
	nml.raw.push("inline", "<span style=\"border-bottom: 1px dashed " .. color .. "\">")
end

function undercustom_end()
	nml.raw.push("inline", "</span>")
end

nml.custom_style.define_toggled("Undercustom Red", "~", function() undercustom_start("red") end, undercustom_end)
nml.custom_style.define_paired("Undercustom Green", "[|", "|]", function() undercustom_start("green") end, undercustom_end)
>%
```

%<[main]
function undercustom_start(color)
	nml.raw.push("inline", "<span style=\"border-bottom: 1px dashed " .. color .. "\">")
end

function undercustom_end()
	nml.raw.push("inline", "</span>")
end

nml.custom_style.define_toggled("Undercustom Red", "~", function() undercustom_start("red") end, undercustom_end)
nml.custom_style.define_paired("Undercustom Green", "[|", "|]", function() undercustom_start("green") end, undercustom_end)
>%
Results in the following:
 * ``Plain Text,~Dashed underline~`` → ~Dashed underline~
 * ``Plain Text,[|Dashed underline|]`` → [|Dashed underline|]

# Limitations

 * Custom styles cannot be removed and will be defined through the entire document
 * Custom styles defined from lua must have their `start` and `end` functions in the `main` lua kernel.