A method for identifying a font displayed within an electronic document. In one embodiment, the method includes a computer processor identifying a string of two or more characters that correspond to a custom ligature within an electronic document, wherein the custom ligature is associated with at least one character of the electronic document. The method further includes accessing a font library associated with the electronic document. The method further includes identifying a font file within the font library that corresponds to the at least one character of the electronic document that is associated with the custom ligature. The method further includes identifying a glyph within the identified font file that corresponds to the custom ligature. The method further includes substituting the identified glyph into the electronic document to replace at least the custom ligature. The method further includes displaying the substituted glyph within the electronic document.