By MDN and W3schools the only letters (commands) avaible in SVG paths are: M/m(moveto), L/z(lineto), H/h(horizontal lineto), V/v(vertical lineto), C/c(curveto), S/s(smooth curveto), Q/q(quadratic Bézier curve), T/t(smooth quadratic Bézier curveto), A/a(elliptical Arc) and Z/z(closepath).
But I just found 'e' (2.52e-4,1.13167) on my SVG file made on Inkscape and I need to know what does it means. The complete path:
<path style="fill:#000000;stroke-width:0.25446901"
d="m 83.846207,283.12668 c 15.992614,-15.1728 -2.513154,-76.38272 -19.662265,-19.85549 -2.686628,2.07836 -3.844405,3.79032 -3.843936,5.68391 2.52e-4,1.13167 1.271934,3.67458 2.424778,4.8488 29.290043,-6.79271 2.902502,8.1524 11.570816,9.81493 1.988533,0.34976 6.85716,0.0978 9.510607,-0.49215 z"
id="path47"
inkscape:connector-curvature="0"
sodipodi:nodetypes="cccccc" />
ps: the code is result of a 'trace bitmap' made on Inkscape
The e is for exponential notation: https://www.w3schools.com/js/js_numbers.asp
2.52e-4 for example means 0.000252 = 2.52 * 10 ^ -4 = 2.52 * 0.0001