Html: Characters allowed for name attribute of input element?

Practical naming conventions

Naming your form controls is much like naming your pets - increasing simplicity makes validation easy and fun, and removes confusion. An ideal naming convention resembles 'custom_1', 'custom_2', that breeds consistency for your back-end processing to feast on. Choose alphanumeric and selected punctuation to maintain clarity and defend your forms against those pesky XSS attacks.

Encoding 101: Be the server tamer

When the curtain call comes, and forms are submitted, the spotlight turns to character encoding. Trust in ASCII characters for universal compatibility. Unleash the beast of non-ASCII characters by employing enctype="multipart/form-data" encoding in POST submissions. PHP developers alert: array-like names (as in, data[]) dance smoothly with your server-side array handling, while periods (you know, data.info) require special love.

Advancing through dynamic environments

If you are dynamically generating input fields (like a coding magician), stick to the golden rules specific to your server-scripting language. In the world of PHP, bracketed names (field[]) are your best friends, facilitating dynamic array-based operations. Albeit, watch out for pesky dot characters in names - servers like Apache may have a sweet spot for replacing foo.bar with foo_bar.

Expert tips for advanced cases

• Non-ASCII know-how: Use non-ASCII cautiously and with correct encoding.
• Server etiquette: Understand how your server interprets . and spaces and adapt accordingly.
• Keeping XSS at bay: Whitelist approach does wonders for input-name based XSS prevention.

Security and an ode to semantics

Whenever in doubt, opt for the id attribute for JavaScript and CSS; let name cater to server-side processing. Sanitize and validate input names on the server side. Remember, in GET requests, names unleash their hidden talents and become part of the URL, mandating the need for URL-safe characters.

Making sense of form names

Think of name attributes as OFC (Official Form Codenames) - important for backend data handling and data sorting. If it were RUMINT (Rumor Intelligence), name attributes enjoy the freedom of being CDATA - liberating, but needs responsibility.

Corner cases in naming

Planning ahead always pays off:

• Form field array names: fieldname[] makes data submission in arrays a breeze—critical for checkboxes or multi-selects.
• Periods in names: Got periods? Check backend handling, and consider replacing with underscores or hyphens (foo-bar).

Compatibility check points

Better safe than sorry:

• Different browsers: Set up play dates between your forms and latest browsers.
• Different server: Ensure your form is familiar with servers (Apache, Nginx).

Don't fall into these traps

Evade the common mistakes:

• Neglected characters: Mind the characters with special meanings in URLs.
• XSS holes: Treat your input names with care; always sanitize against XSS exploits.