I am new to RMarkdown, so maybe I'm missing something. But I've looked for most of this afternoon and still have not found a solution. Hopefully you can help. Here's the problem.

I have a R Notebook to which I am trying to add a list of variable descriptions. Here is a crude set of specifications for the list:

Entire list is indented by, say, 1/2 inch.

Variable symbol (name) is the leftmost item. They are left justified and aligned.

Symbols (names) can be Greek characters, subscripted, or superscripted.

Total width of the symbols range from one to nine characters.

Descriptions are indented at least 3 characters to the right of the widest symbol.

Descriptions are also left-justified and align at the indented horizontal point on the page.

Here is an example of what this might look like (notice I can't left-align the descriptions):

_A_c_ Area of a circle [A sub c]
_π_ Mathematical constant (= 3.14159 ...)
_r_ Radius of a circle
_r^2_ Value of r squared

g_variable Growth rate of "variable"

Here I've had to use markdown to format the column of variables. Here any internal underscores subscript the following term, and a carat (^) superscripts the following term.

How about using a simple table with no header row, plus (optionally) math syntax for the symbols?

This forum's markdown doesn't do simple tables (as far as I can tell), but here's a pipe table as a partial example (pipe tables require a header row):

Symbol

Description

A_c

Area of a circle [A sub c]

\pi

Mathematical constant (= 3.14159 ...)

r

Radius of a circle

r^2

Value of r squared

g_{variable}

Growth rate of "variable"

To achieve the overall indent, you could:

add an empty column (hard to control width precisely, and sort of a hack)

if your output is PDF, it may be better to just use a LaTeX table and take care of the indenting in LaTeX

Here's an example of #1:

Symbol

Description

A_c

Area of a circle [A sub c]

\pi

Mathematical constant (= 3.14159 ...)

r

Radius of a circle

r^2

Value of r squared

g_{variable}

Growth rate of "variable"

And here's the markdown I used:

| Symbol | Description
-------|----------------|--------------------------------------
| $A_c$ | Area of a circle [A sub c]
| $\pi$ | Mathematical constant (= 3.14159 ...)
| $r$ | Radius of a circle
| $r^2$ | Value of r squared
| $g_{variable}$ | Growth rate of "variable"
---------------------------------------------------------------

ETA: One more option, if your output is HTML: use a raw-HTML description list, which has the benefit of being semantically appropriate to your task. You would need to make sure your CSS formatted it the way you want.