I'm looking at the Records of Foreign Service Posts (RG84), Consular Posts, Beirut, Lebanon, Volume 429. I notice under the column for passport numbers, the most common number is 6 digits. Sometimes though, they're only 2 or 4 digits. Does anyone know the

Dear Marilyn,

Thank you for your question.  We reviewed Volume 429 (Passports) from the Beirut Consular Post.  It appears that the numbering was created by the personnel at the Post; unfortunately, we are unable to interpret their numbering system. 

We hope this information is helpful. Best of luck with your research!