encodingtextedit
I've saved files with different encodings using TextEdit. After closing the file, with a vim editor, I open the file and type the following to test for the existence of a byte order mark:
:setlocal bom?
no bom is detected for any encoding.
This script seems to directly create BOMs ok.
#!/usr/bin/env bash
printf '\xEF\xBB\xBF' > withBom.txt
But, I'd like to use a more reliable technique than that to create files with BOM. I don't understand what is going on with TextEdit.
The format menu has a toggle to switch things for you.
Pressing shift + command + T will toggle the document to plain text mode.
You can also set the default format in the preference pane for the app.
First, use TextEdit, don't use Word.
Before you save your document, select Make Plain Text from the Format menu. (If the menu says Make Rich Text then you are already in plain text mode.)
If you save the document now, you should be able to give it whatever extension you want. Since the file is plain text, you can be sure that TextEdit won't add any additional formatting instructions that will turn it into an incorrectly-formatted CSS file.
Best Answer
If I remember right, it's not possible in TextEdit. For BOM you need to use a more serious editor like BBEdit: