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<p class="MsoNormal" style="margin-bottom:12.0pt">Mark Taylor said: <i><o:p></o:p></i></p>
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<i>64-bit integers are often used as source identifiers, e.g. SDSS ObjID and Gaia source_id.  These don't often come in images/arrays but do often come in tables.  I have come across TZEROn = 9223372036854775808 to represent unsigned 64-bit integers (SDSS DR15
 I think).<br>
<br>
</i><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt">The small bodies community in the solar system often uses base-62 to represent large integer values in a small number of digits. Which is more annoying for humans is a matter of opinion: “No that’s big-X little-a…”
 versus “two 8s, three 7’s, a 2, and a 0”.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt">Rob<o:p></o:p></p>
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