Blue Birth Certificate

[lustremounter]

My friend has received her father's Birth Certificate from the M.o.D./ Royal Navy service records.
It was issued in 1929, when he joined the Navy, by the Registrar in Hull and records his birth in 1917.
The layout is exactly the same as the usual red on white certificate except that it is printed in black type on blue paper and has in the corner 'Education Act relating to elementary Education'.
On the back is a pro-forma to be filled in requesting, to the Registrar, the issue of a Birth Certificate.
Also on the back is 'Must not be used for purposes of secondary education'.
The certificate was held by the Navy since 1932 and was released to the next of kin in 2001.
What was the reason for issuing these blue (education) certificates instead of the usual red ones?

Bob.

[stanmapstone]

The Factory and Workshop Act , 1901.
It would  probably be a Certified Copy of an Entry of Birth for the purpose of the above-mentioned act, or for any purpose connected with the EMPLOYMENT in LABOUR or ELEMENTARY EDUCATION of a young person under the age of sixteen, or of a child
.

Stan