Only tangentially related:

In the Quake source code, they have strings to represent the intensity over time of a flickering light source:

https://github.com/id-Software/Quake/blob/bf4ac424ce754894ac...

  // 3 CANDLE (first variety)
  lightstyle(3, "mmmmmaaaaammmmmaaaaaabcdefgabcdefg");

They range from a to z and progress through the string with time, so the candle starts out at medium "m" intensity for a bit before it goes dark ("a") for some time, etc.