ˌɔn θˈɜːɾi wˈʌn mˈɑːɹtʃ nˈaɪntiːnhˈʌndɹɪd twˈɛnti sˈɛvən, ˌɛsˌaɪˈɛs ðæt ˈɪz, ˌɛmˈaɪ sˈɪks pˈæst ˈɛvɪdəns tʊ ˌɛmˈaɪ fˈaɪv, kˈɜːɾəsi əvən ɪnfˈɔːɹmənt ɪnsˈaɪd ˈɑːɹkoʊz, ðæt ˈɑːɹkoʊz hæd ɪlˈiːɡəli pɹəkjˈʊɹd ænd kˈɑːpɪd ɐ klˈæsᵻfˌaɪd sˈɪɡnəlz tɹˈeɪnɪŋ mˈænjuːəl fɹʌmðɪ ˈɔːldɚʃˌɑːt mˈɪlətˌɛɹi bˈeɪs.
On 31 March 1927, SIS (that is, MI6) passed evidence to MI5, courtesy of an informant inside Arcos, that Arcos had illegally procured and copied a classified Signals Training manual from the Aldershot military base.