Lee, it is wonderful to have you posting on this, and of course most appropriate to have you here on this topic!!!
At first I thought this Smithsonian reference was to the Witham swords, which though newsworthy over a period of time, occasionally have been brought to the fore rather sensationalizing the 'mysterious' inscriptions. However, this seems clearly a separate case.
It seems Oakeshott included mention and drawings of some of these 'inscriptions' in his "Archaeology of Weapons", and that he was somewhat of the opinion they were acronyms probably of sacerdotal or other religious significance.
What is interesting is that these apparent acronyms or otherwise sequenced letters and interpolated either glyphs, symbols and perhaps flourished letter characters indeed defy any sort of reliable interpretation.
In the discussion of such inscription on a presently concurrent thread, under "Odd Sword", attempts are made to decipher the letters into some tangible order of translation. Again, it is difficult to determine exactly which alphabet, or combination thereof, might be employed.
I think what we need is a "Rosetta Sword" !!!
In the case of many Italian blades from Brescian regions, with makers Caino and Picinino in particular, there were alphabetic letters used in groupings, but often in repetitive fashion, and reductive in letters removed progressively in some cases. Also, often second lines were using the same letters though shuffled into anagram style groupings.
Obviously this practice defied any tangible acronym decoding, and suggests the letters may have been given numeric or other values or used in symbolic sequencing. The truth remains unknown. What is known is that the practice seems to have been employed in other centers, and in particular may have been filtered either to or from Spain.
While it is tempting to note that Germany certainly must have copied this practice in kind, as of course they spuriously used many Spanish and Italian markings and motif...it is important to recall that this mysterious practice seems present in degree in Frankish weapons earlier and somewhat on these English swords.
A remaining and possibly significant factor is that of the Kabbalah, and the use of gemetria, that is the use of alphabet characters with numeric value and various symbolism representing Kabbalistic dogma and esoterica.
It seems as I understand that the use of acronyms in Hebrew were often pronounced in some degree as words.
Though not suggesting that this particular blade, nor the inscriptions on the others mentioned might be associated to Kabbalist words or phrases, it is worthy to note as possible source of influence.
Again, thank you for adding this Lee,
Best regards,
Jim