 Somewhat similarly, Russellian contents may be modified in order to reflect first-personal indexical contents by introducing contents that are akin to open sentences, with a gap in place of a component corresponding to the subject. In the example involving the red cube, the contents might be something like a structured proposition containing the cube, the non-locational properties it appears to have (e.g., being red, being cubical, and so on), and then a component expressed by ‘two feet in front of ____’, where the gap can be filled in with different subjects in different circumstances. To assess this special semantic entity for accuracy, the gap would need to have a value. Whether its gap is filled or not, this entity is something that in principle two experiences had by different subjects could share. For discussion of these contents for experience, see Bach 1997 (in the Other Internet Resources section below); for a Fregean version of gappy contents see Burge 1991 and Schellenberg 2010; for a Russellian version of gappy contents for belief and utterances, see Braun 1993.