Input 제한(Restrictions) (some are new in HTML5)

Attribute	Description
disabled	Specifies that an input field should be disabled
max	Specifies the maximum value for an input field
maxlength	Specifies the maximum number of character for an input field
min	Specifies the minimum value for an input field
pattern	Specifies a regular expression to check the input value against
readonly	Specifies that an input field is read only (cannot be changed)
required	Specifies that an input field is required (must be filled out)
size	Specifies the width (in characters) of an input field
step	Specifies the legal number intervals for an input field
value	Specifies the default value for an input field

Example

<input type="number" name="points" min="0" max="100" step="10" value="30">
<input type="date" name="bday">

<input type="date" name="bday" max="1979-12-31">

<input type="range" name="points" min="0" max="10">

<input type="month" name="bdaymonth">

<input type="week" name="week_year">

<input type="time" name="usr_time">

<input type="datetime" name="bdaytime">

<input type="datetime-local" name="bdaytime">

<input type="email" name="email">

<input type="search" name="googlesearch">

<input type="tel" name="usrtel">

<input type="url" name="homepage">