(p)SS     Significant Secondary           A statistically significant secondary is highlighted by the MODELSHIFT module. A secondary eclipse is typical of an eclipsing binary star.
(p)CO     Centroid Offset                 A significant photocentre shift is detected. This indicates that the target star is not the source of the investigated signal.
UC        Unreliable Centroids            A centroid image is considered unreliable if stray light, bright field stars or low SNR cause the difference image to be too noisy for proper photocentre measurements.
(p)OED    Odd-Even Difference             A statistically significant difference between odd and even eclipses is highlighted by the MODELSHIFT module and/or the vetters, indicating an eclipsing binary star.
(p)Vshape V-shape                         The shape of the signal is not U-shaped, as expected from a typical transit, but rather V-shaped. A transiting planet (usually with R < <Rstar) is expected to produce a sharp ingress, a flat bottom, and a sharp egress. In contrast, an eclipsing star (usually with R ~ Rstar) often produces gradual ingress and egress.
TD        Too Deep                        For a given stellar radius, the deeper the eclipse, the larger the eclipser. As the deepest confirmed exoplanet eclipses range between 3 and 4 per cent, e.g. (Noyes et al. 2008ApJ...673L..79N; Triaud et al. 2013A&A...551A..80T, Cat. J/A+A/551/A80), we flag signals with depth greater than 2.5 per cent. We note that we do not use TD as the only indicator for a (p)FP as the stellar radius provided in by ExoFOP-TESS might be under/overestimated.
FSCP      Field Star in Central Pixel     TESS pixels cover a sky-projected area of 21 * 21 arcsec^2^ each. This means that other sources might fall within the same pixel of the target and be the true source of the signal.
LCMOD     Light-Curve MODulation          Oscillations in the light curve due to intrinsic and/or rotational variability (potentially due to pulsations or spots) that are not synchronized with the orbital period. These can be produced by either the target itself of by a nearby field star that falls in the aperture used to extract the light curve. Such light curves are generally not indicative of a potential FP.
sync      Synchronous Modulations         Light-curve variations synchronized with the TOI orbital period (or half) are common features of variable binary stars. For example, stars in binary systems with small orbital separations can be deformed into ellipsoids due to tidal effects. The light curves of these systems can show sinusoidal oscillations on half of the eclipses period due to changes in the light-emitting area of the components along the orbital phase, (Shporer 2017PASP..129g2001S). Such light curves are generally indicative of a potential FP.
EB        Eclipsing Binary                An eclipsing binary system.
HPMS      High Proper Motion Star         A high proper motion star as listed on SIMBAD.
SSys      Strong Systematics              The long-cadence ELEANOR light curve displays strong artifacts.
Fla       Flares                          TESS light curve shows potential flaring events. These are sharp rises in flux followed by an exponential decay.
NT        No Transit                      The ELEANOR light curve does not show noticeable transit-like signals for QLP-detected TOIs. The modelshift module flags the candidate due to the low statistical significance of the expected signal.
NS        Nearby Source                   We identify a nearby source that is the true source of the signal. This has been achieved using the eleanor.pixel_by_pixel() function, as explained in Section 4.2.
MD        Momentum Dump                   TESS thruster-firing-induced artefact in the light curve.
LOWSNR    Low Signal to Noise Ratio       The SNR of the expected transits is too low for reliable vetting.