<p>
This colour scheme was devised by Suzanne Duce and the Jalview Team to highlight ambiguity codes used in nucleotide sequences.
</p>
+ <p>
+ The use of X to represent an unknown base is acknowledged, but this is not recommended as the symbol refers to xanthine (see IUPAC-IUB Commission on Biochemical Nomenclature (CBN). <a href="https://iupac.qmul.ac.uk/misc/naabb.html">Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents.</a>)
+ </p>
<div align="center">
<table width="200" border="1">
<tr>
</tr>
<tr>
<td bgcolor="#4f6f6f">X</td>
- <td>Xanthine (sometimes Unknown)</td>
+ <td>Unknown (sometimes Xanthine)</td>
</tr>
<tr>
<td bgcolor="#CD5C5C">R</td>