Having apparently misplaced my old copy of "Ada," I just yesterday received a replacement. Recalling that the Family Tree that precedes the novel (on pages negative 5-4) captured my interest in the old days, I spent some time perusing it.
It was interesting to determine ages at which Veenian ancestors wed each other (Prince Vseslav Zemsky, for example, was over 70 when he wed the 15 year-old Princess Sofia Temnosiniy). But I also noticed a possibly interesting anomaly (or mere, if unlikely, typo?) in the way Lucette's name is transcribed. Five names appear in two forms, for example Ivan (Van) and Adelaida (Ada), but Lucinda's other name uniquely appears in brackts, thus: Lucinda [Lucette]. Assuming this is not a typo, what significance could it have?
Lucette [probably shouldn't be] in brackets?
I automatically assume (arousing) anomalies such as this one to be indicators to puzzles; I read Nabokov as I solve crosswords. I noticed this one too. Both the McGraw-Hill 1969 version and the Vintage Books 1990 version, it seems, has Lucette wrapped in square brackets. It did not seem like a printing/transcription error.
I do not, however, think this particular anomaly is intended. I did some digging to come to that conclusion. One does not consider it to be of any thematic importance (one has tried); it does not correspond with anything in the plot. I have asked a few friends who are familiar with the process of family tree setting about the matter; they say that there are no typographical explanations for the odd pair of square brackets—though they could not know what the Russian standard was in Nabokov's time: after all, it is common practice now to enclose nicknames with inverted commas instead of brackets.
Below I attach a screenshot from two Russian translations of AA, in both of which all nicknames are wrapped by (round) brackets.