Feedback and Markers meaning

[Potter-Win10]

Hi team and community,

First of all, congrats to business and dev teams. The app is amazing for habits tracking, and really stands out among others because of (in my opinion) two main aspects:

1. It maintains a close alignment with its purpose, with pretty straight forward functionalities
2. Even with a large combination of resources and possibilities, the app make it simple and deliver a State of the art UI/UX

Regarding the Markers: besides understanding how it works, in a attempt to improve usage, i was wondering what is the exact definition of each one, and what they mean in a sense of the information they deliver and how they are reflected in the habit dashboard.

For example:

Main screen / items list display

Considering the image, what is the difference between and why are the indicators shown differently? Specially for the dashes - with different color scales, and also the X / 0 (skipped?). Since the value 0 is equal to undone, shouldn't it be displayed as X?

So far, as per my understanding:
For Yes or No
✓ = done
- = skipped
X = missing data or undone?
? = missing data (if enabled)

For Measurable
10 = done (if colored)
- = skipped
0 = missing data or undone?
? = missing data (if enabled)

Screenshots of input fields below

Yes or No input ↓

Measurable input ↓