Notes are short and informal. We can omit pronouns (I, you, he etc), possessive adjectives (my, your etc), articles (the, a etc) and verbs (out = I am out). We can also use abbreviations

Explanation of Informal Note Writing:

Informal notes are characterized by their brevity and casual tone. To achieve this, certain grammatical elements can be omitted or replaced:

• Pronouns: Words like 'I', 'you', 'he', 'she', 'it', 'we', 'they' can be left out when the meaning is clear from context. For example, instead of 'I am out', one might write 'Out'.
• Possessive Adjectives: 'My', 'your', 'his', 'her', 'its', 'our', 'their' can be omitted.
• Articles: 'The', 'a', 'an' are often excluded in informal notes.
• Verbs: Certain verbs, like 'am', 'is', 'are', 'will be', can be abbreviated or implied. For instance, 'I am out' can be shortened to 'Out', and 'Will be' can be represented by 'B'.
• Abbreviations: The use of common abbreviations (e.g., 'U' for 'you', 'B' for 'be', 'etc.' for 'et cetera') further contributes to the concise nature of informal notes.

These conventions allow for quick and efficient communication in informal settings.