# Modified statements
It is possible to modify a pdf using a variety of pdf writing software. Clearly for lending and many other applications we don't want to accept fraudulently modified statements. Spike has implemented a feature to detect modifications: see the product feature guide for authenticity for more.
This guide looks at how modified statements may show up in the Spike online converter.
Modified statements can show up in one of three ways:
- success = the pdf may be successfully processed in the case where the modification didn't impact the pdf structure sufficiently. Always look out for warnings on the score & authenticity fields, even if a statement parses successfully.
- invalid-data-extracted = the statement was identified (i.e. the parser is displayed) but the extraction did not complete successfully.
- unknown-pdf = the modification prevented the statement from being identified (the parser is empty)
