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A block comment in Kotlin is a lexical construct used to instruct the compiler to ignore a specific span of text. It is delimited by the /* character sequence at the beginning and the */ character sequence at the end. The enclosed text can span multiple lines or be placed inline within a single statement. Standard Syntax 
/*
  This text is ignored by the Kotlin compiler.
  It can span multiple lines.
*/

val result = 100 + /* inline block comment */ 50
Nested Block Comments Unlike Java and C++, Kotlin’s lexical analyzer supports nested block comments. When the compiler encounters a nested /*, it increments an internal depth counter and requires a corresponding */ to decrement it before terminating the outer comment. This prevents premature termination errors when commenting out large sections of code that already contain existing block comments. 
/*
  Outer comment begins.

  /*
    Inner nested comment.
    The compiler tracks this depth.
  */

  Outer comment concludes.
*/
KDoc Distinction A block comment that begins with an extra asterisk (/**) is structurally distinct and treated as a KDoc comment. While it shares the same termination syntax (*/) and nesting capabilities as a standard block comment, its contents are parsed into an Abstract Syntax Tree (AST) by the Kotlin documentation engine (Dokka) to generate API references. 
/**
 * KDoc block comment.
 * Parsed for structural documentation rather than strictly ignored.
 */
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