Topic - No.

The numero sign or numero symbol (No., №, and Nº) is a typographic abbreviation of the word number indicating ordinal numeration, especially in names and titles. For example, with the numero sign, the written long-form of the address “Number 22 Acacia Avenue”, is shortened to “Nº 22 Acacia Avenue”, yet both forms are spoken long. Typographically, the numero sign combines the upper-case Latin letter N with a usually superscript lower-case letter o, sometimes underlined, resembling the masculine ordinal indicator. In Unicode, the numero-sign character (U+2116) is intended for Cyrillic writing, and for compatibility with East Asian encodings. - Source: Wikipedia