This is the 1453rd most frequent Dutch word.
nl
"NL" is the abbreviation for "Nederland," meaning "the Netherlands" in English.
Here, 'nl.' is used as an abbreviation for 'namelijk', introducing an example clarifying the preceding statement.
Ik houd van talen, nl. Nederlands en Engels.
I love languages, namely Dutch and English.
In this sentence, 'nl.' elaborates on or specifies the requirement mentioned earlier.
Het document moet in het juiste formaat zijn, nl. PDF.
The document must be in the correct format, namely PDF.
Here, 'nl.' is shorthand for 'namelijk', making explicit the information previously mentioned.