Latexian Help > Text Encodings
Text Encodings specify the format in which text documents are saved to a disk. For documents that contain only English characters and standard punctuation symbols, the "Plain Text (ASCII)" encoding is usually the best choice. This encoding is compatible with the LaTeX and XeTeX typesetters without any configuration required. UTF-8 is often a good encoding choice for documents that contain international characters or special punctuation. UTF-8 is compatible with XeTeX without special configuration; in LaTeX, the following command can be included in the preamble for UTF-8 compatibility:

\usepackage[utf8]{inputenc}
The Open and Save panels in Latexian both allow an encoding to be selected that is different from the default value set in Latexian's Preferences. If you want to select an encoding that will always be used for a specific document, then open the document and then select "Get Info" from the "File" menu. The "Get Info" panel allows an encoding to be selected, which will then become the new default for that document.