A short while ago, I wrote that Odoric of Pordenone's name for the north of Sumatra, Lamori, came from the Arabic al-Rāmnī, a name commonly given to Sumatra as a whole by Arab geographers. This was Henry Yule's supposition, and it seemed fairly reasonable to me.
However, I've been re-reading the Deśawarṇana and the name 'Lamuri' is clearly present in the text, which undermines that notion somewhat. Canto 13 of the poem is about the 'Malay lands' that 'seek refuge and in numbers come into the presence' of Majapahit, which is to say, places where people speak Malay and are (supposedly) vassals of the Javanese. Several of the places mentioned are found in other texts of the same period - the poem was written in the years leading up to 1365 (ś 1287) - including the European ones, so the geographical information is probably reliable (even if the political information isn't necessarily).
Lamuri is listed alongside Samudra, Lampung, and Barus, all very clearly in Sumatra, so it seems far more likely that Odoric and the Arabs derived their names from the same source than that the former borrowed from the latter. Yule wasn't to know this, however. The first extant manuscripts of the poem to be seen by Europeans were looted by the Dutch from Lombok after a military intervention in 1894, well after Yule's Cathay and the Way Thither was published in 1866.
Some of the placenames that appear in European texts are derived from Arabic ones, including Marco Polo's Fansur, almost certainly derived from the Arab name for Barus in western Sumatra. Lamori, however, seems to come straight from the source. The fact that I didn't realise this, despite having read the Deśawarṇana in the past, has spurred me to create a table of all of the ancient Indonesian placenames I can find in original source material (European, Chinese, Indian, Malay, Javanese, &c) so I don't make the same kind of mistake again. I'm going to add to it over time and hopefully release it online when I'm halfway happy with it. I think it would be quite a useful resource.
More about placenames in the Deśawarṇana later.