etc versus eta !!!

[Ben]

ETA is short for estimated time of arrival. As in, "What's our ETA in London?" (asked to the train conductor).

Sorry! You'll have to stick with et al.

[Lynn]

ESL students have to learn how to handle the common Latin abbreviations. However, I see no reason to multiply their confusion by inventing new Latin abbreviations to throw at them. Perhaps your students are more savvy than mine.