of each known pulsar. We first determined if there was $significant$ power at a given (known pulsar) frequency and then determined its period and amplitude, if however there was non-zero power at a low significance level, an upper limit was placed on the pulse-amplitude of the (presumably inactive) pulsar.

For each known pulsar, (i.e those detected at a high level of confidence in one or more observations, or from the literature) an appropriate period search-range was determined from inspection of occurrences detected at $\geq$ 90% significance in a *blind search*. For “literature” pulsars a $\pm$5% frequency band centered on the known period was used. The [Lomb-Scargle periodogram ]{}of each observation was then scanned in this period range, the maximum power identified and its significance estimated, considering only the independent frequencies in the allowed period range. This is the *prior knowledge* significance.

Given that 30 SMC pulsars are known with periods less than 1000 s, allowing for up to 3 harmonics gives a possible 93 genuine signal frequencies. Once period variability and timing resolution are included, the possibility of contamination requires the adoption of an algorithm to reject false detections of pulsars that lie close to the harmonic frequencies of others.

