What these are
The superscript a/o (sometimes underlined) are abbreviations for ordinal numbers used in Spanish, Italian and Portuguese similar to English -th (as in “4th, 5th, 6th..”). The use of “o” vs “a” depends on the gender of the noun. For instance, the “1st American woman” would be 1ª americana in Spanish and the “1st American man” would be 1º americano. The 5th Amercan woman and man would be 5ª americana/5º americano.
I got a request for putting codes for these on the Penn State Web Computing with Accents Web site in various locations, so I thought I would summarize the codes here.
|Feminine Ordinal (ª)||Masculine Ordinal (º)|
|Unicode Code Point||U+00AA (170)||U+00BA (186)|
|Windows Alt Code||ALT+0170||ALT+0186|
|Mac Option Code||Option+9||Option+0|
|HTML Entity Code||ª||º|
But Wait There’s More
But in the land of Unicode, there’s always more to know…such as that in Spanish 1º primero ‘1st.masc’ or ‘1º’ may be shortened to primer which can be abbreviated as ‘1er‘…or that you may write octavo ‘eight.masc’ as 8º or 8.º or possibly 8vo…although Google tends to have more instances of 8º.
What’s important though is that only º and ª have their own code points in Unicode. For English -th, -nd, -rd or Spanish -vo,-er you have to rely on the old fashioned SUP (superscript) tag or its equivalent in CSS.