The right margin and text area is for marks and comments.
The left margin and shape rubrics (see below) are for tracking deducted points.
A deduction of "–X" is a warning that points will be deducted in your next assignment for the same error.
Numbers with letter "S" after are deductions to Clarity and Flow under Scientific Writing on the master rubric: style, reasoning, succintness, incorporation in discussion prompts, etc.
Numbers with letter "M" after are deductions to Proofreading and General Formatting under Mechanics on the master rubric: abstract length, citing tables/figures, grammar, spelling, formatting, units, sig. figs., error, variables defined, overall format, etc.
In the shape rubrics below, a checkmark (✔) means you lost no points for the item and a negative number means you lost that many points for the item. Each shape rubric is assignment specific.