The identifier appears to be a specific file name or database entry, likely associated with a digital book (MOBI format) from an online library or archive system.
: This may represent a date of upload (e.g., April 2009) or a specific batch code used during the digitization process. 000990010eldfdmlibrolandia0409 mobi
: Specific regional digital libraries in Latin America or Spain often use "Librolandia" as a branding for their children's or general fiction portals. The identifier appears to be a specific file
: This is likely a unique accession number or database ID used by a specific library system to catalog the digital file. 000990010eldfdmlibrolandia0409 mobi