The following is from KL's official regulations as per April 1, 2005. The only change I'm aware of since then is that employees with 20 years of uninterrupted service now also qualify for Category A.
Anybody who wants a full copy (all 17 pages) is welcome to drop me a PM, I shall need an e-mail address to send the PDF file to.
"3.2 Priority Serial Number (PSN)
3.2.1 Construction PSN
(1) For the purpose of allocating seats on KLM scheduled services, ISA travelers are assigned a priority serial number (PSN) consisting of four figures.
2) The PSN is determined on the basis of the year in which the employee joined KLM.
[...]
The following rules apply with respect to the following target groups:
• Retired employees, widows, widowers and orphans: PSN as calculated based on the above method + 20 points.
• Employees with an employment contract for at least three months but no longer than one year are automatically awarded a PSN of 2400.
• Family members enjoy the same PSN as the employee concerned.
• Companions and the accompanying staff member have the PSN of the employee concerned plus 250.
3.2.2 Lower PSN
1. Is issued once per year and is valid during one year (January through
December).
2. Is Applicable five years after commencement of employment.
3. Is Applicable to KLM staff, retired staff and their family members.
4. Lower PSN is calculated by reducing PSN (article 3.2.1) by 1000.
5. Children traveling alone do not have a lower PSN.
3.2.3 Category classification
For the purpose of travel at ISA fares on KLM/KLC schedules services, employees are assigned to categories A or B. This classification also applies to their family members.
Retired employees, widows/widowers and orphans retain the category last ssigned during the employee’s term of active service. Insofar as this applies, establishment managers are assigned to the category linked to their actual function group.
Category A includes:
Ground personnel
• concerning ground personnel (including seconded ground personnel) in the Netherlands: employees classified in function group MSG 4 or higher and employees designated as comparable to them by the EVP Human Resources & Industrial Relations;
• establishment managers;
• local ground personnel outside the Netherlands as designated by the manager of the establishment concerned in consultation with the EVP Human
Resources & Industrial Relations.
Flying personnel
• pilots who have been in the employ of KLM and KLM Cityhopper in this capacity for at least eight years or who “officially” receive a function component of at least 1,500;
• (sr.) pursers who have completed 15 years of service with KLM.
All other employees belong to category B.
The transition from category B to category A takes place with effect from the first day of the calendar month in or after which the employee is first assigned to category A.
3.3 Accommodation on KLM/KLC scheduled services
3.3.1 Travel class
(1) Category A
ISA travelers assigned to category A, with the exception of children traveling alone, will be allocated seats successively in C Class or M Class (C/M), insofar as seats are made available in these travel classes and in ascending PSN order (from low to high).
(2) Category B
ISA travelers assigned to category B, with the exception of children traveling alone, will be allocated seats successively in M Class or, insofar as insufficient seats are made available in M Class, in C Class (M/C); seat allocation in C Class will take place in ascending PSN order (from low to high).
(3) Children traveling alone
Children traveling alone will be allocated seats in M Class.
Children are deemed to be traveling alone if they are not accompanied by the
employee or his/her spouse. An employee who is on board as a working or non-working crew member does not qualify as a person accompanying the child.
3.3.2 Order of seat allocation on KLM/KLC scheduled services
On departure, the seats made available will be allocated as follows:
a. A lower PSN has priority over a higher PSN.
b. In cases of an equal PSN, the following order of priority will be observed:
• in transit;
• travel class (C/M takes precedence over M/C);
• most distant destination;
• check-in time;
• date of joining KLM.
If crew seats are made available for passengers by the captain (in consultation with the purser), the passenger handling department will determine which passengers are eligible for them, in accordance with the above order of priority."
The captain and senior purser of course have the authority to reseat pax as they see fit, including upgrading to J, for valid operational reasons, e.g. illness, pax with disabilities, keeping unaccompanied minors away from dirty old men (which nowadays seems to comprise just about every male over 16 flying alone), rescuing pax from drunk neighbors, broken seats, and all that.
What are not valid operational reasons should be obviously clear to everybody, including KL cabin crew: nowhere in the regulations does it say they are entitled to upgrade their friends, neighbors, family, pretty girls or boys, or anybody else they fancy after the doors have closed. Officially, there are strict rules for who may travel in J class, but these are blantantly ignored on a very regular basis. Management surely know, but either couldn't care less or fear the unions and feel it is a price worth paying to keep them happy.
Johan
By the way, I have written to KL about this, and got a fob-off reply.