GroupDocs.Signature for .NET 26.6 – June 2026 Release Highlights ^[draft]

GroupDocs.Signature for .NET 26.6 is now available. This release adds OOXML compliance control for WordProcessing documents, refines the trial‑mode experience for archives and multilayer images, and introduces a multi‑framework NuGet delivery model with dedicated per‑TFM packages.

What’s new in this release

New features

Support and respect OOXML compliance for WordProcessing documents

GroupDocs.Signature now preserves the original OOXML compliance level of WordProcessing documents and lets you override it at save time through the API.

What changed:

• The original OoxmlCompliance value is detected when the document is loaded and preserved on save by default.
• WordProcessingSaveOptions exposes a new nullable OoxmlCompliance property. When null (default), the loaded document’s compliance is kept; when set, it overrides the source value.
• Only honoured for OOXML output formats: Docx, Docm, Dotx, Dotm and their FlatOpc variants.

New enum:

public enum OoxmlCompliance
{
    /// <summary>Specifies ECMA-376 compliance level.</summary>
    Ecma,
    /// <summary>Specifies ISO/IEC 29500:2008 Transitional compliance level.</summary>
    Transitional,
    /// <summary>Specifies ISO/IEC 29500:2008 Strict compliance level.</summary>
    Strict
}

Code example

using (Signature signature = new Signature(filePath))
{
    TextSignOptions signOptions = new TextSignOptions("John Smith")
    {
        Left = 100,
        Top = 100,
        Width = 200,
        Height = 60
    };

    // Force ISO 29500:2008 Strict on save regardless of the source's compliance.
    // Other allowed values: OoxmlCompliance.Ecma, OoxmlCompliance.Transitional.
    WordProcessingSaveOptions saveOptions = new WordProcessingSaveOptions(WordProcessingSaveFileFormat.Docx)
    {
        OoxmlCompliance = OoxmlCompliance.Strict
    };

    SignResult result = signature.Sign(outputFilePath, signOptions, saveOptions);
}

How to get the update

NuGet

Upgrade to the latest package version via NuGet. Choose the package that matches your target framework to download only the required binaries.