Affirmative. Execute the following code:

.my-selector {
    font: initial;
}

It is unfortunate that the limitation of web technologies prevents us from reading the browser's or system's font using CSS or jQuery. The fonts rendered by the browser or system are not accessible to web applications in any way.

Although I attempted a few proofs of concept, I was unable to retrieve the browser's default settings.

We can only hope for updates in W3C standards that may address this issue in the future. In the meantime, I will continue to search for solutions and update you if I come across anything relevant.

In the past, I have faced similar challenges but approached them differently by overriding with the desired font.

However, there is an alternative approach we can explore. We could create a JavaScript function to read the user agent and set specific font families based on different browsers:

var setDefaultFont = {
    Android: function () {
        $('*').css( "font-family", "//FONT USED IN ANDROID BROWSERS" );
    },
    BlackBerry: function () {
        $('*').css( "font-family", "//FONT USED IN BLACKBERRY BROWSERS" );
    },
    iOS: function () {
        $('*').css( "font-family", "//FONT USED IN iOS BROWSERS" );
    },
    Opera: function () {
        $('*').css( "font-family", "//FONT USED IN OPERA BROWSERS" );
    },
    Windows: function () {
        $('*').css( "font-family", "//FONT USED IN WINDOWS BROWSERS" );
    }
};

This solution may not be ideal, but it could potentially work as a workaround for the current limitation.

Although a solution has been provided previously, I wanted to share an alternative approach that could be beneficial:

*, html, body {
     font-family: inherit !important;
}

By using this code snippet, it instructs the root elements of the HTML document to adopt the font style of their parent element. In this scenario, the parent element would typically refer to the browser's user agent styles, resulting in your fonts inheriting characteristics from the default settings.

Your questions have been catching my eye quite frequently, and it seems they revolve around mostly theoretical scenarios. While others have given you some guidance in the right direction, I wanted to share my thoughts on the matter as well.

Exploring Explicit Methods

Currently, there is no direct way in Javascript or CSS to explicitly set the default browser font. The CSS specifications do not allow for this functionality; however, with some creative thinking, you could potentially use Javascript to fetch the font name for explicit usage. While I won't provide actual Javascript code to achieve this due to its complexity, I can shed some light on a possible approach. Please note that this idea may not be foolproof but holds promise.

Structural Concept

Here's a suggestion:

1. Create 5 span nodes like so:

   <span style="font-family: monospace;">Monospace Text</span>
   <span style="font-family: sans-serif;">Sans-Serif Text</span>
   <span style="font-family: serif;">Serif Text</span>
   <span style="font-family: fantasy;">Fantasy Text</span>
   <span style="font-family: cursive;">Cursive Text</span>
   

   Although these generic font families are defaults in browsers, they do not provide an exact font name that an individual might be using. Also, keep in mind that each element has its own default font - not all of them use the same one.

   Consider the distinction between the default browser font and what a user has personally set as their default; this variation makes achieving Rahul Patil's structure somewhat imperfect, despite its general correctness in most cases.

   A Note

   Various elements default to different generic font families, which varies across different browsers. To ensure consistency, implementing a CSS Reset file would be beneficial.

2. Explore tools such as this to identify the font:

   http://www.lalit.org/lab/javascript-css-font-detect/
   

   The font detection tool needs modifications to parse fonts list and match them with defaults. It works by comparing character dimensions, as different fonts vary in size. This difference is more evident at larger font sizes (which is why it uses 72 pixels).

   A Caveat

   An important point to consider is that this method may only work with ASCII/Romanized fonts and could pose challenges with Unicode sets. Adapting it for non-ASCII fonts might require considerable computing resources. Identifying language settings accurately could involve maintaining a database of fonts per language and detecting the browser's language settings reliably (distinct from system settings). Although 'navigator.language' and 'navigator.userLanguage' in Javascript offer insights, they may reflect the operating system language rather than the browser's language. Achieving accurate results might necessitate server-side scripting.

3. Develop a Javascript function to analyze font lists and compare them against the created elements' dimensions from Step 1 above. Utilize Flash to obtain a comprehensive font list. Alternatively, a Java applet may serve this purpose effectively. Some useful resources include:

   https://github.com/gabriel/font-detect-js
   http://font-detect.s3.amazonaws.com/index.html
   

4. By following these steps, you should theoretically discern the specific font utilized by the individual. Extending this process to determine generic fonts for various element types (sans-serif, serif, monospace, etc.) could strain CPU resources and might benefit from a system-level application. One potential solution involves caching conditions for individual users and tailoring CSS accordingly.

Touching on Implicit Approaches

Some contributors have suggested alternative methods; Daniel Lisik notably mentioned employing 'inherit !important' for stringent font-family changes. For instance:

<html>

<head>

<style>

div { font-family: Cursive; }

p { font-family: Inherit !important; }

.serif { font-family: Serif; }
.sans-serif { font-family: Sans-Serif; }

.serif-important { font-family: Serif !important; }
.sans-serif-important { font-family: Sans-Serif !important; }

</style>

</head>

<body>

<div>
    Normal Div Text

    <p>Default P Text</p>

    <p class="serif">Serif</p>
    <p class="sans-serif">Sans-Serif</p>

    <p class="serif-important ">Important, Serif</p>
    <p class="sans-serif-important ">Important, Sans-Serif</p>

</div>

</body>

</html>

• "Normal Div Text" will display in "Cursive"
• "Default P Text" will also appear in "Cursive"
• "Serif" will render as "Cursive"
• "Sans-Serif" will also be styled in "Cursive"
• "Important, Serif" will adopt the "Serif" font style
• "Important, Sans-Serif" will adopt the "Sans-Serif" font style

If you require further clarifications, feel free to ask and I'll provide additional details if needed.

References

http://www.w3.org/TR/CSS21/fonts.html#value-def-generic-family

http://www.w3.org/TR/CSS2/cascade.html#value-def-inherit

Resources

https://github.com/gabriel/font-detect-js

Your inquiry is somewhat ambiguous. Although I may have misunderstood, I will attempt to offer assistance nonetheless.

If you are resolute in adhering to the default browser fonts and font sizes, the following code snippet should serve your purpose:

html, body {
    font-size: 100% !important; 
}

body {
    font-family: serif !important; /* Or sans-serif, monospace or any other suitable choice. */
}

In this case, inheritance should take effect as long as no font stacks or sizes are specified for all other elements.

It's important to consider the cascade order.

This approach would override various stylesheets, with the exception of user stylesheets that incorporate !important declarations on relevant elements. In such scenarios, it is essential to respect the user's preferences.

Personally, I prefer a simpler implementation:

html, body {
    font-size: 100%; 
}

body {
    font-family: serif; /* Or sans-serif, monospace or any other appropriate option. */
}

Hence, refraining from specifying font stacks on every element ensures flexibility for users who may have set their own preferences using !important declarations within their user stylesheet, which takes precedence over a standard author stylesheet.

While the usage of the initial keyword can be an effective strategy, it is not supported by any version of Internet Explorer. Therefore, exploring polyfills, such as those provided by Modernizer or creating custom solutions like polyfill.js, could address compatibility concerns with IE.

Although my response may not be ideal (given the late hour), I hope it proves useful to you in some capacity.

P.S. Your query might pertain to overriding a browser's settings to enforce a specific default font, irrespective of the user's configurations. However, attempting such manipulation would likely be futile, particularly if the user has established their own user stylesheet with font properties designated as !important.

Why not give this method a shot:

.item {
   font-family: -webkit-block;
   font-family: -moz-block
   font-family: -o-block
   font-family: block
}

Additionally, you can experiment with the following alternative that is equally effective:

.item {
   font-family: null;
}