Checked baggage guidelines can vary from airline to airline, so it's crucial to check with the specific airline you are flying with. However, here are some general guidelines that are commonly followed:

1. Weight Limit: Airlines typically have weight limits for checked baggage. The weight limit can vary depending on your ticket class. Exceeding the weight limit may result in additional fees.
2. Number of Bags: The number of checked bags allowed may depend on your ticket class and the airline's policies. Higher class tickets often come with a higher baggage allowance.
3. Size Restrictions: Airlines usually have specific size restrictions for checked baggage. This is typically measured by adding the length, width, and height of the bag. Ensure that your bag meets these requirements.
4. Excess Baggage Fees: If you exceed the allowed weight or number of bags, you may incur excess baggage fees. These fees can vary and can be quite high, so it's important to adhere to the airline's baggage limits.
5. Special Items: If you are carrying special items such as sports equipment, musical instruments, or other oversized items, check with the airline in advance for any specific guidelines or fees associated with these items.
6. Prohibited Items: Certain items are prohibited in checked baggage due to safety and security reasons. These may include flammable liquids, explosives, and other dangerous goods. Familiarize yourself with the airline's list of prohibited items.
7. Baggage Tagging: Ensure that your checked bags are properly tagged with your name, contact information, and destination address. This helps in case your baggage is lost or misplaced.

Excess baggage refers to luggage that exceeds the weight, size, or quantity limits set by the airline. Guidelines for dealing with excess baggage may vary among airlines, so it's crucial to check the specific policies of the airline you are flying with. However, here are some general guidelines that are commonly followed:

1. Excess Baggage Fees: Most airlines charge additional fees for exceeding the permitted weight or number of bags. These fees can vary widely and may increase with the extent of the excess. Some airlines may charge per kilogram (or pound) of excess weight, while others may charge a flat fee.
2. Pre-Payment Options: Some airlines allow passengers to pre-pay for excess baggage online before arriving at the airport. This can sometimes be more cost-effective than paying at the check-in counter.
3. Online Check-in: Some airlines offer the option to check in online and pay for excess baggage in advance. This can streamline the check-in process and potentially save you time at the airport.
4. Limits on Excess Baggage: Airlines may have specific limits on how much excess baggage they will allow per passenger. It's important to be aware of these limits and try to stay within them to avoid complications and higher fees.
5. Prohibited Items: Even if you are willing to pay excess baggage fees, certain items may still be prohibited due to safety or security reasons. Check with the airline regarding any restrictions on the type of items you can include in your baggage.
6. Packing and Repacking: If your baggage exceeds the weight limit, you may have the option to redistribute items among your bags or even purchase an additional piece of luggage to spread the weight. However, this depends on the airline's policies.

While many airlines charge fees for excess baggage, there are certain circumstances in which passengers may be allowed special no-fee baggage privileges. These exceptions can vary depending on the airline and specific situations. Here are some common scenarios where passengers may be eligible for special no-fee baggage allowances:

1. Elite Status or Loyalty Programs: Some airlines offer special baggage allowances as a benefit for passengers with elite status or those enrolled in loyalty programs. Passengers with higher-tier status often receive additional or waived fees for checked baggage.
2. Business and First Class Tickets: Passengers traveling in business or first class generally receive a more generous baggage allowance, and additional fees for excess weight or extra bags may be waived.
3. Military Personnel: Many airlines provide special baggage allowances for active-duty military personnel traveling on official orders. This may include extra weight allowances and waived fees for additional bags.
4. Sports Equipment: Some airlines may allow passengers to check certain sports equipment, such as golf clubs or skis, without incurring additional fees. However, specific rules and allowances vary, so it's essential to check with the airline in advance.
5. Medical Necessities: Passengers with medical needs, such as special equipment or supplies, may be eligible for additional baggage allowances or waived fees. It's advisable to contact the airline in advance and provide any necessary documentation.
6. Infant/Child Items: Airlines typically allow passengers traveling with infants or young children to bring certain essential items, like strollers, car seats, and cribs, without additional fees. However, there may be specific guidelines on size and weight.

Carry-on baggage guidelines can vary between airlines, so it's crucial to check the specific policies of the airline you are flying with. However, here are some general guidelines that are commonly followed:

1. Size Restrictions: Airlines typically specify maximum dimensions (length, width, and height) for carry-on bags. These dimensions may vary, but a common guideline is around 22 x 14 x 9 inches (56 x 36 x 23 cm). It's essential to check the specific requirements of the airline you are using.
2. Weight Limit: While there is often no specific weight limit for carry-on bags, some airlines may have restrictions. If there is a weight limit, it is usually in the range of 15 to 22 pounds (7 to 10 kg). Again, check with the airline for their specific guidelines.
3. Number of Bags: Most airlines allow passengers to bring one carry-on bag and one personal item (such as a purse, laptop bag, or small backpack). The personal item should be small enough to fit under the seat in front of you.
4. Security Screening: All carry-on items must go through security screening. Be prepared to remove laptops and liquids from your bag for separate screening.
5. Prohibited Items: Certain items are prohibited in carry-on baggage due to security regulations. These may include sharp objects, liquids in containers larger than 3.4 ounces (100 ml), and other potentially dangerous items. Check the airline and airport guidelines to avoid issues during security checks.
6. Special Items: Airlines may have specific rules for carrying special items in your carry-on, such as musical instruments, sports equipment, or medical devices. Check with the airline in advance for any additional guidelines or requirements.
7. Space in Overhead Bins: There is limited space in overhead bins, especially on full flights. Try to be considerate of other passengers and use only your fair share of space.

Always check with your specific airline for the most accurate and up-to-date information on their carry-on baggage policies. Adhering to these guidelines helps ensure a smooth boarding process and a comfortable flight for all passengers.