JavaScript has the asynchronous nature, and CroJSDoc provides some tags for documentation asynchronicity.

NodeJS style's callback

Use @nodejscallback.

// (Borrowed from Node.js Manual)

/**
 * Asynchronously reads the entire contents of a file.
 * @param {String} filename
 * @param {Object} [options]
 * @param {String} [options.encoding=null]
 * @param {String} [options.flag='r']
 * @return {String}
 * @nodejscallback
 */
function readFile(filename, options, callback) {
  require('fs').readFile(filename, options, callback);
}

readFile('test', { encoding: 'utf-8' }, function (error, content) {
  console.log(content);
});

# (Borrowed from Node.js Manual)

##
# Asynchronously reads the entire contents of a file.
# @param {String} filename
# @param {Object} [options]
# @param {String} [options.encoding=null]
# @param {String} [options.flag='r']
# @return {String}
# @nodejscallback
readFile = (filename, options, callback) ->
  require('fs').readFile filename, options, callback

readFile 'test', encoding: 'utf-8', (error, content) ->
  console.log content

The result of the above comment:

Promise

Use @promise.

/**
 * Asynchronously reads the entire contents of a file.
 * @param {String} filename
 * @param {Object} [options]
 * @param {String} [options.encoding=null]
 * @param {String} [options.flag='r']
 * @return {String}
 * @promise
 */
function readFile(filename, options) {
  return Promise.promisify(require('fs').readFile)(filename, options);
}

readFile('test', { encoding: 'utf-8' })
.then(function (content) {
  console.log(content);
});

##
# Asynchronously reads the entire contents of a file.
# @param {String} filename
# @param {Object} [options]
# @param {String} [options.encoding=null]
# @param {String} [options.flag='r']
# @return {String}
# @promise
readFile = (filename, options) ->
  Promise.promisify(require('fs').readFile) filename, options

readFile 'test', encoding: 'utf-8'
.then (content) ->
  console.log content

The result of the above comment:

Together

@nodejscallback and @promise can be used together.

/**
 * Asynchronously reads the entire contents of a file.
 * @param {String} filename
 * @param {Object} [options]
 * @param {String} [options.encoding=null]
 * @param {String} [options.flag='r']
 * @return {String}
 * @nodejscallback
 * @promise
 */
function readFile(filename, options, callback) {
  return Promise.promisify(require('fs').readFile)(filename, options)
  .nodeify(callback);
}

readFile('test', { encoding: 'utf-8' }, function (error, content) {
  console.log(content);
});
// or
readFile('test', { encoding: 'utf-8' })
.then(function (content) {
  console.log(content);
});

##
# Asynchronously reads the entire contents of a file.
# @param {String} filename
# @param {Object} [options]
# @param {String} [options.encoding=null]
# @param {String} [options.flag='r']
# @return {String}
# @nodejscallback
# @promise
readFile = (filename, options, callback) ->
  Promise.promisify(require('fs').readFile) filename, options
  .nodeify callback

readFile 'test', encoding: 'utf-8', (error, content) ->
  console.log content
# or
readFile 'test', encoding: 'utf-8'
.then (content) ->
  console.log content

The result of the above comment:

Use ordinary tags

If you don't use NodeJS style's callback or the function returns an other value immediately, you can use ordinary tags.

// (Borrowed from CORMO)

/**
 * Finds a record by id.
 *
 * If a callback is given, it returns the record in the callback.
 * Otherwise, it returns an Query object for chaining.
 * @param {RecordID} id
 * @param {Function} [callback]
 * @param {Error} callback.error
 * @param {Model} callback.record
 * @return {Query}
 */
find = function (id, callback) {}

# (Borrowed from CORMO)

##
# Finds a record by id.
#
# If a callback is given, it returns the record in the callback.
# Otherwise, it returns an Query object for chaining.
# @param {RecordID} id
# @param {Function} [callback]
# @param {Error} callback.error
# @param {Model} callback.record
# @return {Query}
@find: (id, callback) ->

The result of the above comment: