Quinquenio refers to the period of five years in the life of the child inquestion. Are you sure you have the correct spelling of "cartular"?
Saludos de Jaime

Those authorized to make records renew Such authorizations every five years:. ...Abogados y Notarios Públicos de la república de Nicaragua, autorizado el
primero, para cartular durante el quinquenio que terminará el día nueve de
noviembre del año dos mil, el segundo para cartular en un quinquenio que
vence el treinta de noviembre del año dos mil dos, CERTIFICAMOS: que las
firmas que anteceden fueron puestas en nuestra presencia, en la acta de
acuerdo que consta de cinco folios útiles, son autenticas y son las que
utilizan en todos los actos administrativos y jurídicos. Search the URL for "cartular".

Hi,

According to Butterworth's Spanish/English Legal Dictionary, "cartulario" = court clerk, notary public, archivist, registry, or book of records. Given that it's an adoption document, it could be any number of these, so obviously, you'll have to check the context to see which of these fit.

For the Fifth Year Period part, I am assuming that the years were stated after "quinquenio," so you'll have to put the years in after "Fifth Year Period" (example: Fifth Year Period 1990-1995).

Hope that helps.
Cheers,
Mary C. Maloof
Certified Sp > En Translator

in lieu of five year period, I would use a more legal term, such as lustrum or quinquennium.

Cartular is registrar, recorder, etc.

Please note that the office is held during five years, not on the fifth year only!

Good luck on your translation!

Cartular may be a registrar but not necessarily so.
Lustrum=5-year-period (in legal terminology)

I took the phrase from American instruments, where the Notary's seal reads his/her name, registration number and commission expiration date.