>> 100M+ is a bit more than i would expect for an image format. have i not been paying attention

> So at least if GP was talking about libjxl "100K+" would be more accurate.

M can mean thousands and I think it's common to use it used that way in finance and finance-adjacent areas: https://www.chicagomanualofstyle.org/qanda/data/faq/topics/A...:

> A. You’ve identified two commonly used conventions in finance, one derived from Greek and the other from Latin, but neither one is standard.

Starting with the second convention, M is used for amounts in the thousands and MM for amounts in the millions (usually without a space between the number and the abbreviation—e.g., $150M for $150,000 and $150MM for $150 million). This convention overlaps with the conventions for writing roman numerals, according to which a thousand is represented by M (from mille, the Latin word for “thousand”). Any similarity with roman numerals ends there, however, because MM in roman numerals means two thousand, not a thousand thousands, or one million, as in financial contexts...

https://www.accountingcoach.com/blog/what-does-m-and-mm-stan...:

> An expense of $60,000 could be written as $60M. Internet advertisers are familiar with CPM which is the cost per thousand impressions.

> The letter k is also used represent one thousand. For example, an annual salary of $60,000 might appear as $60k instead of $60M.