As often, the "problem" (I'm not sure this is a problem, but this is another subject) that the provider gives the same name for many series (with different dimensions):
Here are the corresponding source data for a random example of problematic values reported by validation script:
"seriesKey":"SEC.M.AT.1000.F33100.N.2.EUR.E.Z","title":"Austria, short-term debt titles, gross issues at nominal value","titleCompl":"(Gross) issues against cash (flows), Short-term securities other than shares, Nominal value, Total economy issuing sector, Euro, denominated in Euro,Austria"
"seriesKey":"SEC.M.AT.12A0.F33100.N.2.EUR.E.Z","title":"Austria, short-term debt titles, gross issues at nominal value","titleCompl":"(Gross) issues against cash (flows), Short-term securities other than shares, Nominal value, MFIs issuing sector, Euro, denominated in Euro,Austria"
"seriesKey":"SEC.M.AT.130D.F33100.N.2.EUR.E.Z","title":"Austria, short-term debt titles, gross issues at nominal value","titleCompl":"(Gross) issues against cash (flows), Short-term securities other than shares, Nominal value, General government, except central government issuing sector, Euro, denominated in Euro,Austria"
BDF also provides titleCompl field that is just the concatenation of dimensions names.
Some options here:
we could concatenate title and titleCompl fields, but this will lead to super long series titles
we could do this only for names that are duplicated
we could decide that duplicated series names is not a problem when those series names are given by provider (in that case we should open an issue to discuss this point and change validation script).
After discussing with @bduye here is our take on that question:
globally, a design goal is to avoid curating data; we just accept to standardize data encoding (e.g. period format or NA values)
we don't store generated series names (from dimension labels) in JSON data, but it is the web API. At some point we will probably do it however, with a common writing layer for fetchers
if the provider provides duplicated series names, we should only issue a warning: it is not an error in itself (it's the job of the series code or the dimensions to distinguish series)
but during the development of the fetcher, a developer would consider those warnings carefully, to avoid doing programmation errors
as a consequence I would not recommend doing any string manipulation using artifical data (like using an incremented number), to make the series name unique, and just keep the original series name
in the case the provider provides a series name exploded in many cells of an Excel spreadsheet (for example), the author of the fetcher should of course concatenate them
in the dashboard we would display a red color for errors, but warnings would be green, and it would be possible to read them
So in your case @bduye I would take only title and add titleCompl to series attributes, or ignore it if it is absolutely equal to dimension labels.