Strax Field Report

Strax Field Report was an umbrella title for a series of in-character advertisements in 2013 and Doctor Who Adventures short stories in 2015 that featured Strax sending reports back to Sontar.

Webisodes
The original "reports" were about episodes of Doctor Who that had not yet aired and thus served as advertisements. Indeed, in at least two of the reports, the character clearly was talking about out-of-universe things, such as the name of episodes and location filming. The "field reports" were all delivered to the public on the web.

Doctor Who Adventures
In 2015, Doctor Who Adventures magazine began incorporating in-universe Strax Field Reports into their Paternoster Gang Investigates short stories. Strax relayed events he experienced by himself and with Madame Vastra and Jenny Flint in transmissions to Sontar.

Cinema introductions
In addition, cinema screenings of the television story The Day of the Doctor featured an introduction by Strax, addressing the audience on the topic of cinema etiquette.

The cinema screening of the Series 8 premiere, Deep Breath, included an introduction, which also featured Strax's fellow Paternoster Gang members Vastra and Jenny Flint, more similarly formatted to the Strax Field Report, where Strax humourously recounts the first twelve incarnations of the Doctor to Sontar, making note of the War Doctor as well as the Tenth Doctor's aborted regeneration, before alerting them to the appearance of the new Doctor.