What do the words "p-type" and "s-type" mean? As explained in various sources (such as that answer), a planet in an s-type orbit orbits one of the stars of a binary star system, whereas a planet in a p-type orbit orbits both stars. A synonym for a p-type orbit (at least in binary star systems, not sure about N-ary systems in general) is &quot;circumbinary&quot;, which is a self-explanatory term.
However, what do &quot;s-type&quot; and &quot;p-type&quot; mean, respectively?
Are &quot;S&quot; and &quot;P&quot; acronyms of anything?
&quot;Satellite type&quot; and &quot;Planet type&quot;.
The terms seem to have been coined by Rudolf Dvorak in 1982 paper &quot;Planetenbahnen in Doppelsternsystemen&quot;

Due to the fact that quasiperiodic orbits exist around stable orbits 3 different types of possible planetary orbits are found: S-types (satellite type orbit around one primary), P-types (orbits around both primaries), and L-types (librating orbits in the vicinity of L4 or L5).

It's not immediatly clear from this whether &quot;P-type&quot; means &quot;planetary type&quot; or &quot;primary type&quot; (and the full paper would be in German and doesn't seem have been digitised).  However in an English paper from 1986 Critical orbits in the elliptic restricted three-body problem.  Dvorak is explict:

There are three types of stable motion for a third massless body that are interesting as regards this problem: the P-type (planet type) surrounding both primary bodies, the S type (satellite type) orbiting one of the primaries and L-type (Librator type) librating around the Langrangian equilibrium points ...