Suggestion for future here.
When reporting these kinds of stations (really any utility station) it is best to include as much info as you can in the first post. For example, others might have heard it and might be able to confirm it, or might be able to hear it the next day and confirm it. Or, if it is not the station you think it is someone else might be able to assist in IDing it by knowing what was on the freq/time/day you heard. But, without more description it is impossible to do this kind of confirmation/assistance.
The following is meant as helpful suggestion, and not a criticism of your post:
In general any mention of a station should have the frequency it was heard on. By convention on HF frequency is generally indicated in kHz, but MHz also works. So 6.930 MHz or 6930 kHz would either one work.
The time of the reception. Nearly universally such time should be in UTC/GMT, but even local time is better than nothing.
Date or day of reception. Some numbers stations transmit only once a week, or only on certain days. For those kinds of stations a date (in UTC date, not local) can be a quick way to accredit the possibility it is what you think it is.
Mode of reception, USB/LSB/AM/etc. Sometimes the difference between one station and another boils down to the transmission mode.
Message format. Particularly with numbers stations format is a key. Yes, I know you said you were going to decode it later, and so you might not know the format yet, but just saying this for completeness here.
T!