> ## Documentation Index
> Fetch the complete documentation index at: https://cstreams.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Known Issues

> Current bugs and limitations

### LLM Processing

* **Non-deterministic** - Each processing run may produce slightly different results due
  to how LLM's work.

* **Field Stability** - While core identifiers (ISBN, DOI, LOC) remain consistent,
  interpretative fields like author names, subtitles, years, and publisher details can
  vary between runs. What are the best [use cases?](/getting-started/use-cases)

### File Operations

* **PDF Writing** - May produce unexpected metadata changes or file corruption. See
  [Evaluation](/analysis-and-iteration/evaluation) for testing strategies to avoid
  unexpected results.

* **Filename Length** - Limited to 255 characters to maintain compatibility across
  different operating systems. Currently tested on macOS only. Windows and Linux support
  is experimental.

* **Unicode Support** - Special characters in filenames can trigger issues on certain
  operating systems.

* **File Validation** - Source PDF corruption scanning is not yet implemented.

* **Language Support** - Primary language support is English. Limited support for
  non-Latin character sets and right-to-left languages. Arabic, Chinese, Japanese and
  Korean text may produce inconsistent results.

### OCR and Vision Analysis

* **Confidence Floor** - Text segments with OCR confidence below 30% are automatically
  discarded. This is a subjective threshold and you'll need to experiment with your own
  documents to find the best balance.
* **Limited Coverage** - Vision analysis is selective, only processing the cover page,
  high-image-content pages (>90%), early pages with poor OCR, and mixed-content layouts.

### Metadata Extraction

* **Edition Filtering** - First editions are automatically discarded from naming. This may
  not be appropriate for all use cases. A configurable setting is planned for the next
  release.
* **Metadata Transfer** - Carrying over existing PDF metadata to the new file is not yet
  implemented.

### Testing Limitations

* **Test Coverage** - Limited test suite focusing mainly on happy paths. Edge cases and
  error conditions need more coverage. See
  [Test Cases](/analysis-and-iteration/test-cases) for current scenarios.

* **Real Test Files** - Need to create actual PDF files for each test case. For example,
  books with many ISBN formats and various edition formats.

  Setting up a benchmark would be helpful. Feedback and ideas for this are greatly appreciated!

See the [Roadmap](/project/roadmap) for planned improvements to these limitations.