I think the cancellation reads - starting to the left of 'No.' and ending below 'DA' in 'AMSTERDAM' - 'BEVOLKINGSREG.' and then - from the final 'M' in 'AMSTERDAM' - 'AMSTERDAM'. I.e., the local register office. Likely a birth certificate, maybe a marriage licence or death certificate. Could also be registration for someone moving into or out of Amsterdam.
For some reason, in some parts of the world, this stamp is referred to as 'gull' design. This is not a gull. Sometimes, it is called 'dove.' I think this is not wholly correct. In Dutch, we call a pigeon and a dove 'duif.'
The stamp was designed by Chris Lebau and depicts a carrier pigeon in flight (see arrow) over the globe. The pigeon is visible at the top. Below it is a circular shape that represents the globe. At the bottom are waves.
The design shows many similarities with his earlier (1921) airmail fee stamp designed by Chris Lebau. Among the air fee paid by these stamps was that for carriage of mail by air between Amsterdam and London. This shows a seagull traversing the North Sea between London and Amsterdam.
Quote: For some reason, in some parts of the world, this stamp is referred to as 'gull' design.
Guilty as charged. Not sure why, but possibility of nomenclature from a Postage Stamp Catalogue. Always known it as a "Gull" no disrespect meant, maybe "Chinese whispers" "Carrier Pigeon" in 1969 Gibbons. An instantaneously recognisable design.
The funny part is that the 1921 air service to London was operated by KLM. In recent times, KLM has associated itself with te 'Swan.' The company has a long history of naming its aeroplanes for birds. The Boeing 737 fleet carries bird names.
In 1934 'Uiver' (a dialect for 'Stork') won the MacPherson Robertson International Air Race handicap classification and was second overall.
From 22 March 1997, the variable value stamps were dispensed from Nagler machines. These printed the value in a bold red typeface. Like the FRAMA machines, the value string had a fixed length of four positions and ran from 0005 Cent to 9995 Cent. The 5 cent was the smallest denomination coin in circulation after the 1 cent coin had been abolished.
Note the shift in the design that is best visible in the red band.
From 28 August 2000, the stamps were dispensed from Hytech machines. These printed the values in strings of variable length. Available values were 5, 10, 25 Cent and in a range of values from 80 Cent up to more than 100 gulden. The values were printed in a bold black typeface.
As before, the stamps had a number printed in black printed on the back. This counted down from 1000 to 0005.
The coulours of the stamp, red, white, and blue represent the Dutch flag. The top right quadrant shows an aerial photograph of the Van Brienenoord Bridge across the Nieuwe Maas River in Rotterdam. In 1989, the second bridge was installed.
From 1918, the Dutch 'Staatsbedrijf der Posterijen, Telegrafie en Telefonie' - Staatsbedrijf der Posterijen en Telegrafie until 1928 -, or PTT had a financial service called 'Postcheque- en Girodienst' ('PCGD'). The objective was to provide a payments account (sight deposit / checking account) for everyone.
Where banking accounts (nine-digit numbers) were called that, those with the PCGD (up to seven-digit numbers) were called 'Giro.' So, "Giro 9933 Natuurmonumenten Amsterdam" was a call for donations to 'Natuurmonumenten' (natural conservation society) residing in Amsterdam to be deposited in their PCGD account number 9933. Deposits would be made or transferred to the account holder's name + place of residence + account number, hence 'Amsterdam.'
PCGD became part of Postbank, that merged into ING Bank. If someone in the Netherlands has an IBAN number of which only the seven or less final digits are non-zero, you will know it used to be an account with PCGD, or 'Giro.'