Serious alternate form of the Drake Equation, or graffiti? Where I live it is very common to see jackets and T-shirts with familiar yet casually garbled or modified content (example)
I recently spotted what looked a lot like the Drake equation on the back of a motorcycle, shown in the photo.
Here is the equation from Wikipedia (more here):
$$N \ = \ R_* \ f_p \ n_e \ f_l \ f_i \ f_c \ L$$
and here is what I can make out from the photo
$$N \ = \ R_* \ f_p \ n_e \ f_l \ X \ X \ L \ B_X$$
where $X$ represents something I can't read, and note that there is a $B$ at the end that doesn't appear in the Wikipedia version.
There are also unspecified callouts on the $N, n_e, B$ and the first &quot;$X$&quot;.
The sleeve also contains text which is only partly visible:
...CATING
...TIONS
...ALAXY

Question: Does this representation seem to reflect a serious new or alternate version of the Drake equation, or is it better or more likely characterized as &quot;art&quot; or graffiti?
Given the font, it's xkcd 384, The Drake Equation.
The two $X$'s are the other $f$ terms from the original Drake equation, while the $B_S$ is &quot;amount of bullshit you're willing to buy from Frank Drake&quot;