In case anyone is wondering what the APIS information is and how it gets transmitted to the airline :
SSR DOCS BA HK1 P/GBR/1234567890/GBR/01JAN76/M/01JAN20/SMITH/PETER JOHN
SSR = code for a service request
DOCS = primary travel document info, one of the APIS types (also DOCO DOCA DOCV DOCP)
P = document type
GBR = issuing country code
GBR = passport
1234567890 = document number
GBR = passenger nationality
01JAN76 = date of birth
M = sex
01JAN20 = document expiry
full names as per document
Some airlines will refuse transportation, and are entitled to do so, unless there is a full match across :
PNR
ETKT
Travel document
APIS field