1 - Allowed file types - png, jpeg, jpg, gif, psd, pdf, xls, doc, docx, txt, css, xlsx, zip
2 - NO spaces in file names. Use hyphens or underscores to fill blanks.
3 - Multiple Files: Click the first file, and then press and hold the Ctrl key. While holding down the Ctrl key, click each of the other files you want to select.