iStudio Publisher uses the recommended Unicode LINE SEPARATOR (0x2028) and PARAGRAPH SEPARATOR (0x2029) code points. However, for historical reasons, text that you import from other applications may contain the old ASCII Line Feed (0xA) and Carriage Return (0xD) code points. On importing into iStudio Publisher these code points are filtered automatically (i.e. identified and have their values mapped) in order to maintain their correct meaning, otherwise the paragraph endings would be lost and text would be imported as a single paragraph.
If you import text as an RTF (Rich Text Format) file page breaks will be recognised and maintained. Here's how this works. Inside an RTF file page breaks are declared as /page markup. When an RTF file is imported into iStudio Publisher the /page markup is converted first to a Unicode Form Feed (0xC) code point and then subsequently to a Unicode PARAGRAPH SEPARATOR (0x2029). Each paragraph that follows a page break has its “Start at Top of Column” checkbox set automatically.
NOTE: On the Paragraph Inspector there’s a Start at Top of Column checkbox. If you insert the text cursor into any paragraph and select this checkbox it will move that paragraph to start at the top of the next column or flow-linked text container.