8.21. Countries are encouraged to compiled metadata in the course of the process of statistics production, and metadata should be used to ensure consistency of the resulting data. Nevertheless, in the setting up of new statistical processes, a certain flexibility should be allowed in order to give fluidity to the creation process. This Guide recommends using the following good practices, as applicable, in the compilation of tourism statistics metadata:
(a) As an initial step, begin by identifying all possible existing data sources. Compile an inventory of all sources that are related to tourism statistics and that shall be used either as an input or for reference purposes, in order to place tourism statistics within the general framework of official statistics. It is a good practice to establish the format of such an inventory following the recommendations contained in the UNWTO publication entitled Tourism Statistics Metadata Project: General Guidelines for Documenting Tourism Statistics;
(b) While developing tourism statistics metadata, make use, as appropriate, of the metadata concepts and definitions that have been defined in line with IRTS 2008;
(c) Once the process is in place, apply the reference metadata framework in order to document its results. It is very likely that a general metadata policy is already in place in related statistical domains. Tourism statistics compilers are advised to review such metadata carefully and make use of them, as necessary;
(d) Establish metadata registries. A metadata registry is a central repository (preferably formated as a database) which allows linkage of the metadata items used in the descriptions of particular statistical data set;
(e) Incorporate structural metadata items into the data processing as early as possible. It is advisable for structural metadata to be made an integral part of the national tourism statistics database, so that they can be extracted together with any data item and used in data processing to enable meaningful combined data sets to be obtained;
(f) Presentation of reference metadata. Reference metadata can be presented as detailed explanatory notes describing the scope, coverage, and quality of data and made available electronically alongside the database or in special publications;
(g) Institutional arrangements for metadata compilation. Metadata should be seen as part of the process of statistical development and should therefore be part of the overall work programme of the inter‑institutional governance structure put in place to develop the System of Tourism Statistics (see sect. D below).