Dutch language:

A Frankish identity emerged and so did their Frankish or Franconian language. The language itself is poorly attested. A notable exception is the Bergakker inscription, found near the Dutch city of Tiel, which may represent a primary record of 5th-century Frankish. Although some placenames recorded in Roman texts could arguably be considered as the oldest "Dutch" single words, like vadam (modern Dutch: wad, English: "mudflat"), the Bergakker inscription yields the oldest evidence of Dutch morphology, but there is no consensus on the interpretation of the rest of the text.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". To which century do some researchers attribute the Bergakker inscription?
5th