When you have a hyphenated surname, an apostrophe in the surname or a double surname, delete the hyphen/apostrophe and replace with a space while entering the family name in the last name field.
for example MR. JAMES ROBERT BRYCE-BUCHANAN as
Single letter family name
When you have a single letter family name, double the single letter and update in the last name field followed by the given names. Etihad system inhibits the surname, only when the single letter is I, Z, B and C as there letters are used for infant, stretcher and group bookings respectively.
for example MISS MOAN Y as
When names in a booking being created are an exact match, whenever possible add middle names and/or different titles if applicable to make them unique for differentiation, else create a separate booking. For example;