In XML processing with XSLT: which document tells the XSLT processor how to transform the elements of a source XML document into another format (such as HTML, text, or a different XML shape)?

Introduction / Context:
XSLT (Extensible Stylesheet Language Transformations) is the W3C standard language for transforming XML data into other formats. To run a transformation, the processor needs instructions that describe the mapping from source nodes to output. This question asks you to identify the artifact that contains those instructions.

Given Data / Assumptions:

• The source is a well-formed XML document.
• The transformation is performed by an XSLT processor.
• We are targeting an output such as HTML, plain text, or another XML.

Concept / Approach:
The XSLT stylesheet (commonly a .xsl or .xslt file) contains template rules, match patterns, and instructions (for-each, apply-templates, value-of, etc.). The processor reads the stylesheet and applies those rules to the input XML tree to generate the result tree.

Step-by-Step Solution:

Verification / Alternative check:
Any typical XSLT run uses an XML input, an XSLT stylesheet, and produces a result; if the stylesheet is missing, no mapping rules exist.

Why Other Options Are Wrong:

• HTML page: an output format, not the transformation rule-set.
• DOCTYPE procedure: DOCTYPE declares a DTD, not transformation logic.
• Stored procedure: a database concept, unrelated to XSLT.

Common Pitfalls:
Confusing the output HTML file with the stylesheet that generated it; the stylesheet is the transformation specification.

Final Answer:
Stylesheet