# Why do tables use lower-case o's in prefixes? Are they zeroes?

I often consult tables to determine where a station I'm hearing is located. I use them to answer questions like "TF, that's Iceland, right?" or "4X, where is that?".

In every table I've found, the prefixes are upper case, except some of them contain a lower-case 'o'. For instance, FOo belongs to Austral Islands and HBo belongs to Liechtenstein.

From how they are positioned, it would make sense to read them as zeroes, but then again some other prefixes are printed with zeroes. For instance, both this and this table say KH0 belongs to Mariana Isl., though they also list the o-prefixes.

#### What's going on? And why?

Is it a simple matter of someone using the convention of 'o' for zeroes once, everyone copying that table without checking it, and then adding prefixes with zeroes without realising there's a conflict?

Or have I completely misunderstood, and the lower-case o's mean something completely different?

• In some fonts, the numbers are designed to appear like lowercase letters: see en.wikipedia.org/wiki/Text_figures or fonts.com/content/learning/fontology/level-3/numbers/…. My guess would be that the original source material used that typesetting style, where a 0 as part of a longer number would be clear but on its own when mixed in with capital letters ends up looking like a lower-case o instead. Oct 24 at 19:14