\startluacode

local classes = fonts.protrusions.classes
local vectors = fonts.protrusions.vectors

classes.myown = {
    vector = 'myown',
    factor = 1,
}

vectors.myown = table.merged (vectors.quality, {

    [0x002C] = { 0, 2 }, -- comma

})

\stopluacode

\starttext

\showframe

\definefontfeature[whatever][default][protrusion=quality]

\definedfont[Serif*whatever] \setupalign[hanging] \input tufte

\definefontfeature[whatever][default][protrusion=myown]

\definedfont[Serif*whatever] \setupalign[hanging] \input tufte

\stoptext
