Translated as writing / handwriting or scripture / script , I believe that Chanel were trying to highlight how similar this liner is to a pen / writing. It looks like a felt tip pen you used to use when you were in primary school (however luckily no small children have been able to blunt the end trying to colour in as hard as possible!)
Because if it's design, this liner feels so naturally easy to apply. And unlike most liquid liners, it stays black almost like a gel liner.
Although it is not as thick as a gel liner, it does still give a really good effect. As you can see from the photo below, the Chanel liner is really black.