Found the following hamletworks.org entries referring to line 544
View Commentary Note for 543
543
This aboue all, to thine owne selfe be true
1.3.78
View Commentary Note for 544
544
And it must followe as the night the day
1.3.79
View Immaterial Textual Note for 544
544
And it must followe as the night the day
1.3.79
View Material Textual Note for 544
544
And it must followe as the night the day
1.3.79