-<p>This option is available in Jalview Desktop (when adding sequences by any supported method), and Jalview applet (adding from textbox).
-The additional options below apply to Jalview Desktop only.</p>
+ <a name="opensplit" />
+ <p>
+ <strong>Opening a Split Frame View</strong>
+ </p>
+ <p>A Split Frame View can be opened in one of the following ways:</p>
+ <p>
+ <strong><em>Add Sequences</em></strong>
+ </p>
+ <p>
+ If you add (coding) DNA sequences to an open peptide alignment, or
+ vice versa, <em>and</em> at least one DNA sequence translates to one
+ of the peptide sequences, then the option to open in a split window
+ is offered. The DNA may include start and/or stop codons, but no
+ non-coding (intron) sequence.<br> If more than one cDNA variant
+ is present in the alignment, Jalview will first try to match these
+ to protein sequences based on any retrieved cross-references, and
+ failing that, pairwise as they are ordered in the alignments.
+ <p>This option is available in Jalview Desktop (when adding
+ sequences by any supported method), and Jalview applet (adding from
+ textbox). The additional options below apply to Jalview Desktop
+ only.</p>